#include <bits/stdc++.h>

using namespace std;

ifstream in("text.in");
ofstream out("text.out");

int main() {
    string s;
    getline(in, s);

    int length = 0, count = 0;
    regex r("[a-zA-Z]+");
    for (auto it = sregex_iterator(s.begin(), s.end(), r); it != sregex_iterator(); it++) {
        length += it->str().size();
        count++;
    }

    out << length / count;

    return 0;
}