#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
using namespace std;

using ll = long long;
using P = pair<int, int>;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    vector<int> a(n);
    for(int i = 0; i < n; ++i)  cin >> a[i];

    ll X = (ll)n * (n - 1) / 2, X2 = (ll)n * (n - 1) * (2 * n - 1) / 6;
    ll Y = 0, XY = 0;
    for(int i = 0; i < n; ++i){
        Y += a[i];
        XY += (ll)i * a[i];
    }

    double b = (double)(n * XY - X * Y) / (n * X2 - X * X);
    double d = (double)(X2 * Y - XY * X) / (n * X2 - X * X);
    double cost = 0.0;
    for(int i = 0; i < n; ++i){
        double goal = b * i + d;
        cost += (a[i] - goal) * (a[i] - goal);
    }

    cout << fixed << setprecision(15);
    cout << d << ' ' << b << '\n';
    cout << cost << '\n';

    return 0;
}