import java.util.Scanner;
public class Main{
public static void main(String[]args){
Scanner sc = new Scanner(System.in);
int a = sc.nextInt();
int sum=0;
while(a!=0){
sum = sum+a%10;
a = a/10;
}
System.out.println(sum);
}
}

京公网安备 11010502036488号