#include <bits/stdc++.h>
 
using namespace std;
 
ifstream f("text.in");
ofstream g("text.out");

char ch;

int main(){
	int lch = 0, nrch = 0 , L = 0;

	while(f.get(ch)){
		if(isalpha(ch)) L++;
		else{
			if(L > 0) nrch++, lch += L, L = 0;
		}
	}
	if(L > 0) nrch++, lch += L, L = 0;
	//g << lch << " " << nrch << "\n";
	g << lch / nrch;
}