#include <bits/stdc++.h>
using namespace std;
int main(){
  int n; cin >> n;
  vector<double> v(n);
  for (int i = 0; i < n; i++) cin >> v[i];
  double sum_x = n * (n+1) / 2; double sum_y = 0;
  double sum_xx = n * (n+1) * (2*n+1) / 6; double sum_xy = 0;
  for (int i = 0; i < n; i++) {
    sum_y += v[i]; sum_xy += v[i] * (i+1);
  }
  double a = (sum_xy * n - sum_x * sum_y) / (sum_xx * n - sum_x * sum_x);
  double b = (sum_xx * sum_y - sum_xy * sum_x) / (sum_xx * n - sum_x * sum_x);
  printf("%.8f %.8f\n", a+b, a);
  double c = 0;
  for (int i = 0; i < n; i++) {
    b += a;
    c += (v[i] - b) * (v[i] - b);
  }
  printf("%.8f\n", c);
  return 0;
}