#include <bits/stdc++.h>
using namespace std;
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    string s;
    getline(cin, s);
    int cnt = 0;
    for (int i = 0; i < s.length(); i++)
        if ('0' <= s[i] && s[i] <= '9' ||
            'a' <= s[i] && s[i] <= 'z' ||
            'A' <= s[i] && s[i] <= 'Z')
            cnt++;
    cout << cnt << "\n";
    return 0;
}