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

using namespace std;

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

char c;
long long int nr, nrr;

int main() {
	bool ok = false ;
	while (in.get(c)) {
		if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) nrr++;
		else if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) nr++;
		
	}
	out << nrr / nr;

}