// text.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

//#include "pch.h"
#include <iostream>
#include <regex>
#include <fstream>
#include <string>

using namespace std;


class Solver {

public:

	explicit Solver(istream&& in) {
		__readData(in);
	}

	
	int result() const {
		return nrWords ? lengthWords / nrWords : 0;
	}

private:

	void __readData(istream& in) {

		string _line;
		while (getline(in, _line)) {
			__result(_line);
		};
	}

	void __result(string& line) {
		regex e{ "([a-zA-Z]+)" };
		smatch match;

		for (; regex_search(line, match, e); line = match.suffix()) {
			++nrWords;
			lengthWords += match[0].length();
		}

	}

	int nrWords = 0, lengthWords = 0;
};

int main()
{
	ofstream{ "text.out" } << Solver{ ifstream{"text.in"} }.result();
}