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

#define rep(i,a,b) for(int i=a;i<b;i++)
typedef long long ll;

int main(){
    int n;
    cin >> n;
    vector<int> arr;
    rep(i,0,n){
        int t; cin >> t; arr.push_back(t);
    };

    double sumx = (n)*(n-1)/2;
    double sumy = accumulate(arr.begin(),arr.end(),0);
    double sumx2 = 0; rep(i,0,n) sumx2 += pow(i,2);
    double sumxy = 0; rep(i,0,n) sumxy += arr[i] * i;

    double a = (n * sumxy - sumx * sumy)/(n * sumx2 - sumx * sumx);
    double b = (sumx2 * sumy - sumxy * sumx)/(n * sumx2 - sumx * sumx);

    printf("%.8f %.8f\n", b, a);

    double ans = 0;
    rep(i,0,n) ans += pow((arr[i]-(a*i+b)),2);
    printf("%.8f\n", ans);

}