#include <fstream>

using namespace std;

long citire() {
	ifstream fin ("text.in");
	char c;
	long l = 0, s = 0, nr = 0;
	c = ' ';
	while (!fin.eof()){		
		l = 0;
		while (!fin.eof() && (c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z')) {
			l++;
			fin.get(c);		
		}
		if (l) {
			s += l;
			nr++;
		}
		else 
			fin.get(c);		
	}
	fin.close();
	return s / nr;
}


int main() {
	ofstream fout("text.out");
	fout << citire();
	fout.close();
	return 0;
}