#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	int N;
	cin >> N;
	vector<int> Y(N);
	REP(i, N) scanf("%d", &Y[i]);
	ll xsum = (ll)N * (N - 1) / 2, ysum = 0, xysum = 0;
	ll x2sum = 0;
	REP(i, N) {
		x2sum += (ll)i * i;
		ysum += Y[i];
		xysum += (ll)i * Y[i];
	}
	
	double a = (double)xsum * ysum - (double)N * xysum;
	a /= (double)xsum * xsum - (double)N * x2sum;
	
	double b = (ysum - xsum * a) / N;
	
	double c = 0;
	REP(i, N) c += pow(a * i + b - Y[i], 2);
	
	printf("%.16f %.16f\n%.16f\n", b, a, c);
}