#include<iostream>
#include<vector>
#include<cmath>
#include<cstdio>
#include<assert.h>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
int main(){
	ll n;
	cin>>n;
	assert(2<=n&&n<=1000);
	vi in(n);
	rep(i,n)cin>>in[i];
	rep(i,n)assert(0<=in[i]&&in[i]<=100000);
	ll n1=n*(n-1)/2,n2=n*(n-1)*(2*n-1)/6;
	ll sum1=0,sum2=0;
	rep(i,n){
		sum1+=in[i];
		sum2+=in[i]*i;
	}
	double b=(double)(n2*sum1-n1*sum2)/(n*n2-n1*n1);
	double d=(double)(n*sum2-n1*sum1)/(n*n2-n1*n1);
	double c=0;
	rep(i,n)c+=pow(in[i]-(d*i+b),2);
	printf("%.7f %.7f\n%.7f\n",b,d,c);
}