#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;
typedef pair<ll, pair<ll, ll> > P3;

const ll MOD = ll(1e9 + 7);
const ll LLINF = LLONG_MAX;
const int IINF = INT_MAX;
const int MAX_N = int(2e5) + 5;
const double EPS = 1e-8;
int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};
#define SORT(v) sort((v).begin(), (v).end())
#define SORTR(v) sort((v).rbegin(), (v).rend())
#define REP(i, n) for (int i = 0; i < n; i++)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define FOR(i, m, n) for (ll i = m; i < n; i++)
#define ALL(v) (v).begin(), (v).end()

int main() {
    int n;
    double a[1005], as = 0.0, axs = 0.0;
    cin >> n;
    REP(i,n){
        cin >> a[i];
        as += a[i];
        axs += a[i]*i;
    }
    double x1 = n*(n-1)/2, x2 = n*(n-1)*(2*n-1)/6;
    double d = (n*axs-x1*as)/(n*x2-x1*x1),
           b = (x2*as-axs*x1)/(n*x2-x1*x1),
           c = 0.0;
    REP(i,n)c += (a[i]-(d*i+b))*(a[i]-(d*i+b));
    printf("%.8lf %.8lf\n%0.8lf\n",b,d,c);
    return 0;
}