#include <bits/stdc++.h>

using namespace std;

int main() {
    ifstream in("text.in");

    int lg_totala = 0;
    int nr_cuvinte = 0;

    string cuvant;
    while (in >> cuvant) {
        int nr_litere = 0;
        for (char ch : cuvant) {
            if (isalpha(ch)) {
                nr_litere += 1;
            }
        }
        lg_totala += nr_litere;
        nr_cuvinte += 1;
    }

    ofstream out("text.out");
    out << (lg_totala / nr_cuvinte) << endl;
}