[백준] 2475번

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

public class Main {
   public static void main(String[] args) throws IOException {
      Scanner sc = new Scanner(System.in);

      int ans = 0;   // 검증수

      for (int i = 0; i < 5; i++) {
         int num = sc.nextInt();
         ans += num * num;
      }
      System.out.println(ans % 10);
   }
}