#include <iostream>
#include <algorithm>
#include <string>
#include <string.h>
#include <fstream>

using namespace std;

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

char c;
int nr = 1, nrr = 0;

int main() {
	bool ok = false;
	while(in.get(c)){
		int sr = c;
		if ((sr <= 89 && sr >= 65) || (sr <= 122 && sr >= 97) || (sr <= 57 && sr >= 48)) {
			nrr++;
			ok = true;
		}


		if (sr == 32 || sr == 45) {
			if (ok == true) {
			nr++;
			ok = false;
		   }
		}		
	}
	out << nrr / nr;

}