#include<fstream>
using namespace std;

int main()
{
	//open the file
	ifstream input;
	input.open("lines.txt");
	if(!input)
	{
		cout<<"Error opening input file"<<endl;
		exit(0);
	}

	//read from the file. Calculate sum and count
	double num;
	double sum=0;
	int count=0;

	while(!input.eof()) //read as long as we're not at the end of the file
	{
		input>>num;
		sum= sum + num;
		count++;
	}

	sum = sum/count; //average

	cout<<"The average is "<<sum<<endl;

}