/* -*- coding: utf-8 -*-
 *
 * 731.cc:  No.731 等差数列がだいすき - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 1000;

/* typedef */

/* global variables */

double ys[MAX_N];

/* subroutines */

/* main */

int main() {
  int n;
  scanf("%d", &n);

  double xsum = 0.0, x2sum = 0.0, xysum = 0.0, ysum = 0.0;
  for (int i = 0; i < n; i++) {
    scanf("%lf", &ys[i]);

    xsum += i;
    x2sum += i * i;
    xysum += i * ys[i];
    ysum += ys[i];
  }

  double e = n * x2sum - xsum * xsum;
  double d = (n * xysum - xsum * ysum) / e;
  double b = (x2sum * ysum - xysum * xsum) / e;

  double ddsum = 0.0;
  for (int i = 0; i < n; i++) {
    double dy = (b + d * i) - ys[i];
    ddsum += dy * dy;
  }
  
  printf("%.14lf %.14lf\n%.14lf\n", b, d, ddsum);

  return 0;
}