#include <stdio.h>
#include <string.h>

int f(char *str) {
    int n = 0;
    int length = strlen(str);

    for (int i = 0; i < length; i++) {
        char c = str[i];
        switch (c) {
            case '0':
            case '6':
            case '9':
                n += 1;
                break;
            case '8':
                n += 2;
                break;
            default:
                break;
        }
    }

    return n;
}

int main() {
    char str[100001];
    scanf("%s", str);
    int n = f(str);
    printf("%d", n);

    return 0;
}