Two string - using " " to concatenate two input string, and then .Split to separate them.

Twostring19.cs

using System;
using System.Collections.Generic;
using System.IO;
class Solution {
    static void Main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */
        int noOfTestCases = Convert.ToInt32(Console.ReadLine());
        string[] testCases = new string[noOfTestCases];
        for(int i =0; i < noOfTestCases; i++){
            testCases[i] = Convert.ToString(Console.ReadLine()) + " " + Convert.ToString(Console.ReadLine());
        }
        for(int ii = 0; ii < noOfTestCases; ii++) {
            string str1 = testCases[ii].Split(' ')[0];
            string str2 = testCases[ii].Split(' ')[1];
            bool isTrue = false;
            for (char ch = 'a'; ch <= 'z'; ch++) {
                if(str1.Contains(ch.ToString()) && str2.Contains(ch.ToString()) ){
                    isTrue = true;
                    break;
                }
            } 
            
            if(isTrue){
                Console.WriteLine("YES");
            }
            else{
                Console.WriteLine("NO");
            }
        }
    }
}