#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vint;
typedef pair<int,int> pint;
typedef vector<pint> vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define REP(i,n) for(int i=n-1;i>=(0);i--)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define all(v) (v).begin(),(v).end()
#define eall(v) unique(all(v), v.end())
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
const int MOD = 1e9 + 7;
const int INF = 1e9;
const ll INFF = 1e18;


int main() {
	int n; cin >> n;
	vector<double> a(n); {
		rep(i, n) cin >> a[i];
	}

	double x = 0, x2 = 0, y = 0, y2 = 0, xy = 0;
	rep(i, n) {
		x += i;
		x2 += i * i;
		y += a[i];
		xy += i * a[i];
	}


	double ans_a = (n * xy - x * y) / (n * x2 - x * x);
	double ans_b = (x2 * y - xy * x) / (n * x2 - x * x);
	double ans = 0; {
		rep(i, n) {
			double act = ans_a * i + ans_b;
			ans += pow(act - a[i], 2);
		}
	}
	printf("%.9f %9f\n", ans_b, ans_a);
	printf("%.9f\n", ans);
}