Mock1_3

import java.util.Scanner;


public class Main {



    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int sum = 0;

        while(true){
            String number = scanner.nextLine();
            int a = number.charAt(0) - '0';
            int b = number.charAt(1) - '0';
            int c = number.charAt(2) - '0';

            if(a+c != b){
                break;
            }

            sum +=  Integer.parseInt(number);
        }
        System.out.println(sum);
    }


}