[백준] 11720번

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

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

      int N = sc.nextInt();
      String num = sc.next();
      sc.close();

      int result = 0;    // 결과

      for (int i = 0; i < N; i++) {
         result += num.charAt(i) - '0';
      }
      System.out.println(result);
   }
}