#include<iostream>
#include<fstream>
#include<iomanip>
using namespace std;
int main(void)
{
	fstream f,g;
	f.open("text.in",ios::in);
	g.open("text.out",ios::out);
	char c,c2='.';
	int nrlit=0,sumlit=0,nrcuv=0;
	while(f>>noskipws>>c)
	{
		
		if(isalpha(c))
			nrlit++;
		
		else
			if(isalpha(c2))
			{
				sumlit+=nrlit;
				nrcuv++;
				nrlit=0;
			}
		c2=c;	
	}
	g<<sumlit/nrcuv;
}