#include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>

using namespace std;

int main()
{
    string s;
    int count = 0;
    getline(cin, s);
    // cout << s.length() << endl;
    for (int i = 0; i < s.size(); i++)
    {
        if(s[i] >= '0' && s[i] <= '9')
        {
            count ++;
        }
    }
    cout << count << endl;
    return 0;
}