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

int main(void)
{
    int     sum = 0;
    char    c;

    while ((c = getchar()) != EOF) {
        if (c == '\n') {
            break;
        } else if (isdigit(c)) {
            sum += (c - 0x30);
        }
    }
    printf("%d\n", sum);

    return 0;
}