#include <fstream.h>
#include <string.h>

int litera (char caracter)
{
	if (((caracter>='a') && (caracter<='z')) || ((caracter>='A') && (caracter<='Z'))) return 1;
	return 0;
}

int main ()
{
	char sth;
	int i, x;
	long nr_cuv=0, nr_lit=0;
	ifstream ins;
	ins.open ("text.in");
	while (!ins.eof())
	{
		sth=ins.get();
		x=0;
		if (litera (sth))
		{
			nr_cuv++;
			nr_lit++;
			x=1;
		}
		while (x==1)
		{
			sth=ins.get();
			x=0;
			if (litera (sth))
			{
				nr_lit++;
				x=1;
			}
		}
		if (ins.eof()) break;
	}
	ins.close();
	ofstream ous;
	ous.open ("text.out");
	ous<<nr_lit/nr_cuv;
	ous.close();
	return 0;
}