#include<iostream>

using namespace std;

int main()
{
    char a[101];

    fgets(a, 101, stdin);

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

    cout << sum << endl;

    return 0;
}