#include <iostream>
#include <vector>
#include <iomanip>

using namespace std;
using ll = long long;
using vi = vector<int>;

#define in(v) v; cin >> v;
void ins() {}
template<class T,class... Rest>void ins(T& v,Rest&... rest){cin>>v;ins(rest...);}
#define rep(i,n) for(int i=0,_i=(n);i<_i;++i)

int main() {
  int N;
  ins(N);

  vi A(N);
  rep(i, N) {
    cin >> A[i];
  }
  cout << fixed << setprecision(15);

  ll diff = 0;
  rep(i, N-1) diff += A[i+1] - A[i];

  ll B = 0, B2 = 0;
  rep(i, N) {
    B += A[i] * (N-1) - diff * i;
    B2 += A[i] * N - diff * i;
  }
  double b = 1.0 * B / (N-1) / N,
         d = 1.0 * diff  / (N-1);
  double b2 = 1.0 * B / N / (N+1),
         d2 = 1.0 * diff  / N;

  double ans = 0, ans2 = 0;
  rep(i, N) {
    ans += 1.0 * (A[i] - b - d * i) * (A[i] - b - d * i);
    ans2 += 1.0 * (A[i] - b2 - d2 * i) * (A[i] - b2 - d2 * i);
  }
  if (ans < ans2)
    cout << b << " " << d << endl << ans << endl;
  else
    cout << b2 << " " << d2 << endl << ans2 << endl;


  return 0;
}