11720 : 숫자의 합

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int TC = sc.nextInt();
		int sum = 0;
		sc.nextLine();

		String str = sc.nextLine();

		for (int tc = 1; tc <= TC; tc++) {

			sum += str.charAt(tc-1) - '0';
		}
		System.out.println(sum);
	}
}