#include <stdio.h>

main() {
    char str[100000];
    long sum = 0;
    
    scanf("%s", str);
    
    for (int i=0; i<100000; i++) {
        if (str[i] == 0)
            break;
        if (str[i] >= '0' && str[i] <= '9')
            sum += str[i] - '0';
    }
    
    printf("%d\n", sum);
}