#pragma GCC target("avx2")
#pragma GCC optimize("03")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std; typedef long double ld; typedef long long ll;
typedef unsigned long long ull;
#define endl "\n"
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define rep(i,n) for(int i=0;i<(n);i++)
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define ALL(x) (x).begin(), (x).end()
constexpr int INF=1<<30; constexpr ll LINF=1LL<<60; constexpr ll mod=1e9+7; constexpr int NIL = -1;
template<class T>inline bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>inline bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
template<class T>inline int popcount(T a) {return __builtin_popcount(a);}
template<class T>inline T emod(T a, T p) { return (a%p + p) % p;}
//-------------------
ld a[1005];
int main() {
    cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(15);
    int n; cin >> n;
    rep(i,n) cin >> a[i];

    ld s1 = 0.0, s2 = 0.0, s3 = 0.0, s4 = 0.0;
    rep(i,n) {
        s1 += i;
        s2 += i*i;
        s3 += a[i];
        s4 += a[i]*i;
    }

    ld d = ((ld)n * s4 - s3 * s1) / ((ld) n * s2 - s1 * s1);
    ld b = (s2 * s3 - s1 * s4) / ((ld) n * s2 - s1 * s1);


    cout << b << " " << d << endl;

    ld res = 0.0;
    auto f = [](ld x) {return x * x;};
    rep(i, n) {
        res += f(a[i] - b - i*d); 
    }
    cout << res << endl;
    return 0;
}