#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() 
{
    int n, sum=0;
    scanf("%d", &n);
    while (n != 0)
    {
        sum += (temp % 10);
        n /= 10;
    }
    printf("%d",sum);
    return 0;
}