#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
using ll = long long;

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

    int n;
    cin >> n;

    ll c = 0, x = 0, y = 0, x2 = 0, y2 = 0;
    for (int i = 0; i < n; i++) {
        int a;
        cin >> a;

        c += i * a;
        x += i;
        y += a;
        x2 += i * i;
        y2 += (ll)a * a;
    }

    double a = (double)(n * c - x * y) / (n * x2 - x * x);
    double b = (y - a * x) / n;
    double t = a * a * x2 + 2 * a * b * x - 2 * a * c + y2 - 2 * b * y + b * b * n;

    printf("%.9f %.9f\n%.9f\n", b, a, t);

    return 0;
}