#include <bits/stdc++.h>

using namespace std;
ifstream f("text.in");
ofstream g("text.out");

int main()
{
    long long cuv = 0, lit = 0;
    char c;
    f >> noskipws;
    f >> c;
    while (!f.eof()) {
        if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
            ++cuv;
            while ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
                ++lit;
                f >> c;
            }
        }
        else {
            f >> c;
        }
    }
    g << lit / cuv;
    return 0;
}