#include <stdio.h>
#include <ctype.h>

int main(int argc, const char * argv[]) {
    int c = 'a';
    int ans = 0;

    while ((c = getchar_unlocked()) != EOF) {
        if (isdigit(c)) {
            ans += c - '0';
        }
    }

    printf("%d\n", ans);

    return 0;
}