#include <bits/stdc++.h>
#define rep(i,a,b) for(int i=a;i<(b);++i)
#define erep(i,a,b) for(int i=a;i<=(int)(b);++i)
#define per(i,a,b) for(int i=(a);i>(b);--i)
#define eper(i,a,b) for(int i=(a);i>=b;--i)
#define pb push_back
#define mp make_pair
#define INF (1<<30)-1
#define MOD 1000000007
#define all(x) (x).begin(),(x).end()
#define vii vector<int>
#define vll vector<long long>
using namespace std;
typedef long long ll;
typedef pair<int,int> Pii;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
int dy[]={0, 0, 1, -1};
int dx[]={1, -1, 0, 0};
int gcd(int a,int b){return b?gcd(b,a%b):a;}
int lcm(int a,int b){return a/gcd(a, b)*b;}

int n;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
    cin >> n;
    vector<double> a(n), x(n);
    rep(i, 0, n) {
        cin >> a[i];
        x[i] = i;
    }
    double xsum = 0, ysum = 0, xysum = 0, x2sum = 0;
    rep(i, 0, n) {
        xsum += i;
        ysum += a[i];
        xysum += i * a[i];
        x2sum += i * i;
    }
    double d = (n * xysum - xsum * ysum) / (n * x2sum - (xsum * xsum));
    double b1 = (x2sum * ysum - xysum * xsum) / (n * x2sum - (xsum * xsum));
    double cost = 0;
    rep(i, 0, n) {
        cost += (a[i] - (b1 + i * d)) * (a[i] - (b1 + i * d));
    }
    printf("%.15f %.15f\n%.15f\n", b1, d, cost);
    return 0;
}