#include <iostream>
#include <cstdio>
using namespace std;

int main(){
    string s1;
    int cnt=0;
    getline(cin,s1);

    for(int i=0;s1[i];i++)
    if ( s1[i]>='0' && s1[i]<='9')
    cnt++;



    printf("%d",cnt);

    return 0;
}