java 2475

import java.io.*;
import java.util.StringTokenizer;

public class Main {

    public static void main(String[] args)throws IOException {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());

        int result = 0;

        for (int i = 0; i < 5; i++) {
            result = (int) (result + Math.pow(Integer.parseInt(st.nextToken()),2));
        }

        result = result%10;

        System.out.println(result);

        br.close();
    }
}