Java - 백준 코딩테스트 11720번 [문자열 - 숫자의 합]

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class SumOfNums {
 
    public static void main(String[] args) throws IOException {
        // 20210624 - 11720번
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        
        int num = Integer.parseInt(br.readLine());
        String str = br.readLine();
        
        int sum = 0;
        
        for (int i = 0; i < num; i++) {
            sum += str.charAt(i) - '0';
        }
        
        System.out.println(sum);
    }
}