#include <iostream>

using namespace std;

int main()
{
	int num;
	int sum = 0;
	int counter = 0;
	float avg;
	cin >> num;
	while(num != -1)
	{
		counter ++;
		sum = sum + num;
		cin >> num;
	}
	
	avg =  float(sum)/counter;
	cout << "Average: " << avg << endl;
	return 0;
}