#include<iostream>
#include<fstream>
#include<cctype>
using namespace std;

int main()
{
	ifstream inFile("text.in");
	ofstream outFile("text.out");

	char c;
	int number_of_characters = 0, number_of_words = 0;
	char ends_a_word[] = " ,.!?:;\"()[]\\\n\t@#$%^&*=+-";
	while (inFile.get(c))
	{
		if (isalpha(c))
		{
			number_of_characters++;
			char temp = inFile.peek();
			{
				if (strchr(ends_a_word, temp))
					number_of_words++;
			}
		}
	}

	outFile << number_of_characters / number_of_words;
}