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

int
main(void)
{
    enum { CODE_ZERO = 48 };
    unsigned int sum = 0;
    int ch;
    do {
        ch = getchar_unlocked();
        if(isdigit(ch)) {
            sum += ch - CODE_ZERO;
        }
    } while(ch != EOF);
    printf("%u\n", sum);
    return 0;
}