#include <bits/stdc++.h>

using namespace std;

int main(void)
{
	cin.tie(0);
	ios::sync_with_stdio(false);

	int n;
	long double t;
	vector <long double> x, y;

	cin >> n;

	for (int i = 0; i < n; i++)
	{
		cin >> t;
		y.push_back(t);
		x.push_back(i);
	}

	long double X = 0;
	long double Y = 0;
	long double XY = 0;
	long double XX = 0;

	for (int i = 0; i < n; i++)
	{
		X += x[i];
		Y += y[i];
		XY += (x[i] * y[i]);
		XX += (x[i] * x[i]);
	}
	
	long double d = (n * XY - X * Y) / (n * XX - X * X);
	long double b = (XX * Y - XY * X) / (n * XX - X * X);
	long double res = 0;
	for (int i = 0; i < n; i++)
	{
		long double val = i * d + b;
		res += (val - y[i]) * (val - y[i]);
	}
	cout << fixed;
	cout.precision(9);

	cout << b << ' ' << d << '\n';
	cout << res << '\n';

	return 0;
}