gistfile1.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Scanner;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;



public class Exam_Problem3_Biggest3PrimeNumbers {

    public static void main(String[] args) {
    	//inputNumbers contains all numbers from the input
    	List<String> inputNumbers= new ArrayList<>();
    	int result=0;
	Scanner scanner = new Scanner(System.in);
	//input 
	String input = scanner.nextLine();
	//find numbers from the input -> write them in inputNumbers 
	Pattern nums = Pattern
		.compile("[0-9]+");
	Matcher matcher = nums.matcher(input);
	while (matcher.find()) {
	  inputNumbers.add(matcher.group());
	}
	List<Integer> intList=new ArrayList<>();
	List<Integer> primeNums=new ArrayList<>();
	//str to int -> intList contains all nums as integers, instead of strings
			for(String inputNumber : inputNumbers) intList.add(Integer.valueOf(inputNumber));
	//check if numbers in intList are prime
	for (int len = intList.size(),i=0; i < len; i++) {
		int n=intList.get(i);
		//check for prime numbers
		//  13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97};
		if((n==2)||(n==3)||(n==5)||(n==7)||(n==11)||(n==13)||(n==17)||(n==19)||(n==23)||(n==29)||(n==31)||(n==37)||(n==41)||(n==43)||(n==47)||(n==53)||(n==59)||(n==61)||(n==67)||(n==71)||(n==73)||(n==79)||(n==83)||(n==89)||(n==97)){
	        //all prime numbers go in primeNums
	    	primeNums.add(n);
	    }
	}
	//
	//for (int len = primeNums.size(), i = 0; i < len; i++) {
	 //int s = primeNums.get(i);
	//}
	//primes contains prime numbers w/o duplicates
	Set<Integer> primes = new HashSet<Integer>(primeNums);
	if(prime.size()>=3){
		int len=prime.size();
	//array of prime numbers - primeArr object ->arr
	Object[] primeArr=prime.toArray();
	//length of primeArr
	int lenPrimeArr=primeArr.length;
	int arr[]=new int[lenPrimeArr];
for (int i = 0; i < lenPrimeArr; i++) {
	 arr[i]=(int) of[i];
}
Arrays.sort(arr);
	int num1=arr[len1-1];
	int num2=arr[len1-2];
	int num3=arr[len1-3];
	int sum=num1+num2+num3;
	//int sum=num1+num2+num3;
	System.out.println(sum);
	}else{
		System.out.println("No");
	}
}}