#include <stdio.h>

int main(void)
{
        char s[10000] = {};
        int i, sum = 0;

        scanf("%s", s);
        for(i = 0;; i++){
                if(48 <= s[i] && s[i] <= 57){
                        sum += s[i] - '0';
                }
                else if(!(65 <= s[i]))
                        break;
        }
        printf("%d\n", sum);

        return 0;
}