#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)

// approximate 2-d data points with y = ax + b
template <typename T>
pair<double, double> leaset_squares(const vector<T> &x, const vector<T> &y) {
  int n = x.size();
  double x1 = 0;
  double x2 = 0;
  double y1 = 0;
  double xy = 0;

  REP (i, n) {
    x1 += x[i];
    x2 += 1.0 * x[i] * x[i];
    y1 += y[i];
    xy += 1.0 * x[i] * y[i];
  }

  double a = (n * xy - x1 * y1) / (n * x2 - x1 * x1);
  double b = (x2 * y1 - xy * x1) / (n * x2 - x1 * x1);

  return {a, b};
}


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

  int n;
  cin >> n;
  vector<int> x(n), y(n);

  REP (i, n) {
    x[i] = i;
    cin >> y[i];
  }

  auto [a, b] = leaset_squares(x, y);
  double ret = 0;

  REP (i, n) {
    double tmp = y[i] - (b + a * i);
    ret += tmp * tmp;
  }

  cout << fixed << setprecision(12);
  cout << b << " " << a << endl;
  cout << ret << endl;
  
  return 0;
}