made in China

#include <stdio.h>
	#include <iostream>
	#include <string.h>
	using namespace std;
	char a[289819];
	int main()
	{
		double sum = 0 , l = 0;
		while(cin >> a)
		{
			l++;
			sum += strlen(a);
		 } 
		 printf("%.1lf\n",sum/l);
	}