Compressor

package javaapplication1;

import java.util.ArrayList;
import java.util.Scanner;

public class JavaApplication1 {

    
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("What letters would you like to compress?");
        String letters = input.next();
        int counter = 0;
        //System.out.println(letters.charAt(0));
               letters += "1";
        int size = letters.length();
        ArrayList <String> list = new ArrayList<>();
 
        for (int i = 0; i < size-1; i++) {
            if ((letters.charAt(i)) == (letters.charAt(i+1))) {
                //System.out.println(letters.charAt(i));
                counter++;
                //list.add(String.valueOf(letters.charAt(i)));
                
                
               
            }
            else{
                list.add(String.valueOf(letters.charAt(i)) + String.valueOf(counter + 1));
                counter = 0;
            }

        }
        
        
        System.out.println("~~~~~~~~~~~~~~~~~");
        for(int i = 0; i < list.size();i++){
            System.out.print(list.get(i));
        }

    }

}