#include <bits/stdc++.h>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;
typedef unsigned long long ull;


int main(){
  int N;
  cin >> N;
  vector<double> v;
  rep(i,N){
    double x;
    cin >> x;
    v.push_back(x);
  }

  double xysum = 0;
  rep(i,N) xysum += i * v[i];
  double xsum = 0;
  rep(i,N) xsum += i;
  double ysum = 0;
  rep(i,N) ysum += v[i];
  double x2sum = 0;
  rep(i,N) x2sum += i * i;

  double a = (N * xysum - xsum * ysum) / (N * x2sum - (xsum * xsum));
  double b = (x2sum * ysum - xysum * xsum) / (N * x2sum - (xsum * xsum));

  double c = 0;
  rep(i,N){
    double f = b + a*i;
    c += (v[i] - f) * (v[i] - f);
  }

  printf("%.12lf %.12lf\n", b, a);
  printf("%.12lf\n", c);
  
  return 0;
}