#include <fstream>
#include <string>
using namespace std;
ifstream cin("text.in");
ofstream cout("text.out");
string S; long long N, CUV, RAP;
int main(){
	while(cin >> S){
		CUV++;
		for(int i = 0; i < S.length(); i++){
			if((S[i] >= 'A'&& S[i] <= 'Z' ) || (S[i] >= 'a' && S[i] <= 'z')) N++;
		}
	}
	RAP =  N/CUV;
	cout << RAP;
	return 0;
}