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

int main()
{
    char c;
    int64_t sum = 0;
    while (scanf("%c", &c) == 1)
    {
        if (isdigit(c))
        {
            int a = (int)c - 48;
            sum += a;
        }
    }
    printf("%ld" "\n", sum);

    return 0;
}