Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.8.1+commit.df193b15.js&optimize=false&runs=200&gist=

3ed65c3f2c13d5171d3af6b496fd06aa...1_Storage.sol

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.7.0 <0.8.0;

/**
 * @title Storage
 * @dev Store & retrieve value in a variable
 */
contract Storage {

    uint256 number;

    /**
     * @dev Store value in variable
     * @param num value to store
     */
    function store(uint256 num) public {
        number = num;
    }

    /**
     * @dev Return value 
     * @return value of 'number'
     */
    function retrieve() public view returns (uint256){
        return number;
    }
}

3ed65c3f2c13d5171d3af6b496fd06aa...2_Owner.sol

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.7.0 <0.8.0;

/**
 * @title Owner
 * @dev Set & change owner
 */
contract Owner {

    address private owner;
    
    // event for EVM logging
    event OwnerSet(address indexed oldOwner, address indexed newOwner);
    
    // modifier to check if caller is owner
    modifier isOwner() {
        // If the first argument of 'require' evaluates to 'false', execution terminates and all
        // changes to the state and to Ether balances are reverted.
        // This used to consume all gas in old EVM versions, but not anymore.
        // It is often a good idea to use 'require' to check if functions are called correctly.
        // As a second argument, you can also provide an explanation about what went wrong.
        require(msg.sender == owner, "Caller is not owner");
        _;
    }
    
    /**
     * @dev Set contract deployer as owner
     */
    constructor() {
        owner = msg.sender; // 'msg.sender' is sender of current call, contract deployer for a constructor
        emit OwnerSet(address(0), owner);
    }

    /**
     * @dev Change owner
     * @param newOwner address of new owner
     */
    function changeOwner(address newOwner) public isOwner {
        emit OwnerSet(owner, newOwner);
        owner = newOwner;
    }

    /**
     * @dev Return owner address 
     * @return address of owner
     */
    function getOwner() external view returns (address) {
        return owner;
    }
}

3ed65c3f2c13d5171d3af6b496fd06aa...3_Ballot.sol

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.7.0 <0.8.0;

/** 
 * @title Ballot
 * @dev Implements voting process along with vote delegation
 */
contract Ballot {
   
    struct Voter {
        uint weight; // weight is accumulated by delegation
        bool voted;  // if true, that person already voted
        address delegate; // person delegated to
        uint vote;   // index of the voted proposal
    }

    struct Proposal {
        // If you can limit the length to a certain number of bytes, 
        // always use one of bytes1 to bytes32 because they are much cheaper
        bytes32 name;   // short name (up to 32 bytes)
        uint voteCount; // number of accumulated votes
    }

    address public chairperson;

    mapping(address => Voter) public voters;

    Proposal[] public proposals;

    /** 
     * @dev Create a new ballot to choose one of 'proposalNames'.
     * @param proposalNames names of proposals
     */
    constructor(bytes32[] memory proposalNames) {
        chairperson = msg.sender;
        voters[chairperson].weight = 1;

        for (uint i = 0; i < proposalNames.length; i++) {
            // 'Proposal({...})' creates a temporary
            // Proposal object and 'proposals.push(...)'
            // appends it to the end of 'proposals'.
            proposals.push(Proposal({
                name: proposalNames[i],
                voteCount: 0
            }));
        }
    }
    
    /** 
     * @dev Give 'voter' the right to vote on this ballot. May only be called by 'chairperson'.
     * @param voter address of voter
     */
    function giveRightToVote(address voter) public {
        require(
            msg.sender == chairperson,
            "Only chairperson can give right to vote."
        );
        require(
            !voters[voter].voted,
            "The voter already voted."
        );
        require(voters[voter].weight == 0);
        voters[voter].weight = 1;
    }

    /**
     * @dev Delegate your vote to the voter 'to'.
     * @param to address to which vote is delegated
     */
    function delegate(address to) public {
        Voter storage sender = voters[msg.sender];
        require(!sender.voted, "You already voted.");
        require(to != msg.sender, "Self-delegation is disallowed.");

        while (voters[to].delegate != address(0)) {
            to = voters[to].delegate;

            // We found a loop in the delegation, not allowed.
            require(to != msg.sender, "Found loop in delegation.");
        }
        sender.voted = true;
        sender.delegate = to;
        Voter storage delegate_ = voters[to];
        if (delegate_.voted) {
            // If the delegate already voted,
            // directly add to the number of votes
            proposals[delegate_.vote].voteCount += sender.weight;
        } else {
            // If the delegate did not vote yet,
            // add to her weight.
            delegate_.weight += sender.weight;
        }
    }

    /**
     * @dev Give your vote (including votes delegated to you) to proposal 'proposals[proposal].name'.
     * @param proposal index of proposal in the proposals array
     */
    function vote(uint proposal) public {
        Voter storage sender = voters[msg.sender];
        require(sender.weight != 0, "Has no right to vote");
        require(!sender.voted, "Already voted.");
        sender.voted = true;
        sender.vote = proposal;

        // If 'proposal' is out of the range of the array,
        // this will throw automatically and revert all
        // changes.
        proposals[proposal].voteCount += sender.weight;
    }

    /** 
     * @dev Computes the winning proposal taking all previous votes into account.
     * @return winningProposal_ index of winning proposal in the proposals array
     */
    function winningProposal() public view
            returns (uint winningProposal_)
    {
        uint winningVoteCount = 0;
        for (uint p = 0; p < proposals.length; p++) {
            if (proposals[p].voteCount > winningVoteCount) {
                winningVoteCount = proposals[p].voteCount;
                winningProposal_ = p;
            }
        }
    }

    /** 
     * @dev Calls winningProposal() function to get the index of the winner contained in the proposals array and then
     * @return winnerName_ the name of the winner
     */
    function winnerName() public view
            returns (bytes32 winnerName_)
    {
        winnerName_ = proposals[winningProposal()].name;
    }
}

3ed65c3f2c13d5171d3af6b496fd06aa...artifacts...ChatTest.json

{
	"deploy": {
		"VM:-": {
			"linkReferences": {},
			"autoDeployLib": true
		},
		"main:1": {
			"linkReferences": {},
			"autoDeployLib": true
		},
		"ropsten:3": {
			"linkReferences": {},
			"autoDeployLib": true
		},
		"rinkeby:4": {
			"linkReferences": {},
			"autoDeployLib": true
		},
		"kovan:42": {
			"linkReferences": {},
			"autoDeployLib": true
		},
		"görli:5": {
			"linkReferences": {},
			"autoDeployLib": true
		},
		"Custom": {
			"linkReferences": {},
			"autoDeployLib": true
		}
	},
	"data": {
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			"sourceMap": "26:380:0:-;;;;8:9:-1;5:2;;;30:1;27;20:12;5:2;26:380:0;;;;;;;"
		},
		"deployedBytecode": {
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			"sourceMap": "26:380:0:-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;305:98;;8:9:-1;5:2;;;30:1;27;20:12;5:2;305:98:0;;;;;;;;;;;;;;;;;;;;;;;80:91;;8:9:-1;5:2;;;30:1;27;20:12;5:2;80:91:0;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;186:109;;8:9:-1;5:2;;;30:1;27;20:12;5:2;186:109:0;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;23:1:-1;8:100;33:3;30:1;27:10;8:100;;;99:1;94:3;90:11;84:18;80:1;75:3;71:11;64:39;52:2;49:1;45:10;40:15;;8:100;;;12:14;186:109:0;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;305:98;354:7;380:9;:16;;;;373:23;;305:98;:::o;80:91::-;141:9;156:7;141:23;;39:1:-1;33:3;27:10;23:18;57:10;52:3;45:23;79:10;72:17;;0:93;141:23:0;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;:::i;:::-;;;80:91;:::o;186:109::-;240:6;272:9;282:5;272:16;;;;;;;;;;;;;;;;;;;265:23;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;186:109;;;:::o;26:380::-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;:::i;:::-;;;:::o;:::-;;;;;;;;;;;;;;;;;;;;;;;;;;;:::o"
		},
		"gasEstimates": {
			"creation": {
				"codeDepositCost": "177200",
				"executionCost": "220",
				"totalCost": "177420"
			},
			"external": {
				"getMessage(uint8)": "infinite",
				"getMessagesCount()": "410",
				"sendMessage(string)": "infinite"
			}
		},
		"methodIdentifiers": {
			"getMessage(uint8)": "4ea43115",
			"getMessagesCount()": "3d0c46d0",
			"sendMessage(string)": "469c8110"
		}
	},
	"abi": [
		{
			"constant": true,
			"inputs": [],
			"name": "getMessagesCount",
			"outputs": [
				{
					"name": "",
					"type": "uint256"
				}
			],
			"payable": false,
			"stateMutability": "view",
			"type": "function"
		},
		{
			"constant": false,
			"inputs": [
				{
					"name": "message",
					"type": "string"
				}
			],
			"name": "sendMessage",
			"outputs": [],
			"payable": false,
			"stateMutability": "nonpayable",
			"type": "function"
		},
		{
			"constant": true,
			"inputs": [
				{
					"name": "index",
					"type": "uint8"
				}
			],
			"name": "getMessage",
			"outputs": [
				{
					"name": "",
					"type": "string"
				}
			],
			"payable": false,
			"stateMutability": "view",
			"type": "function"
		}
	]
}

3ed65c3f2c13d5171d3af6b496fd06aa...artifacts...ChatTest_metadata.json

{
	"compiler": {
		"version": "0.4.26+commit.4563c3fc"
	},
	"language": "Solidity",
	"output": {
		"abi": [
			{
				"constant": true,
				"inputs": [],
				"name": "getMessagesCount",
				"outputs": [
					{
						"name": "",
						"type": "uint256"
					}
				],
				"payable": false,
				"stateMutability": "view",
				"type": "function"
			},
			{
				"constant": false,
				"inputs": [
					{
						"name": "message",
						"type": "string"
					}
				],
				"name": "sendMessage",
				"outputs": [],
				"payable": false,
				"stateMutability": "nonpayable",
				"type": "function"
			},
			{
				"constant": true,
				"inputs": [
					{
						"name": "index",
						"type": "uint8"
					}
				],
				"name": "getMessage",
				"outputs": [
					{
						"name": "",
						"type": "string"
					}
				],
				"payable": false,
				"stateMutability": "view",
				"type": "function"
			}
		],
		"devdoc": {
			"methods": {}
		},
		"userdoc": {
			"methods": {}
		}
	},
	"settings": {
		"compilationTarget": {
			"3ed65c3f2c13d5171d3af6b496fd06aa/chat_test.sol": "ChatTest"
		},
		"evmVersion": "byzantium",
		"libraries": {},
		"optimizer": {
			"enabled": false,
			"runs": 200
		},
		"remappings": []
	},
	"sources": {
		"3ed65c3f2c13d5171d3af6b496fd06aa/chat_test.sol": {
			"keccak256": "0x417d8f2d2937f664822f001b8867155a7a76f8e54c21bd8343e5c877fdffab22",
			"urls": [
				"bzzr://2d16f578f201994c240aadb493fe2b2499363c87c8460f2979de3d6effb1923c"
			]
		}
	},
	"version": 1
}

3ed65c3f2c13d5171d3af6b496fd06aa...chat_test.sol

pragma solidity ^0.4.18;

contract ChatTest {

    string[] _messages;
    
    function sendMessage(string memory message) public {
        _messages.push(message);
    }
    
    
    function getMessage(uint8 index) public view returns (string memory) {
        return _messages[index];
    }
    
    function getMessagesCount() public view returns (uint256) {
        return _messages.length;
    }

}