#include <fstream>
#include<iostream>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
int main()
{
	int l=0,t=0,c=0;
	char a;
	while(fin.get(a))
	{
		if(('a'<=a&&a<='z')||('A'<=a&&a<='Z'))l++;
		else{
			if(l)c++;
			t+=l;
			l=0;
		}
	}
	fout<<t/c;
	fin.close();
	fout.close();
	return 0;
}