#include <bits/stdc++.h>

using namespace std;

int main() { string s;

getline(cin, s);

int count = 0;

for (int i = 0; i < s.size(); i++) {
  
    if (s[i] >= '0' && s[i] <= '9') {
        count++;
    }
}


cout << count << endl;
return 0;

}