#include<iostream>
#include<iomanip>
using namespace std;
int N,A[1000];
main()
{
	cin>>N;
	for(int i=0;i<N;i++)cin>>A[i];
	double xb=0,yb=0;
	for(int i=0;i<N;i++)
	{
		xb+=i;
		yb+=A[i];
	}
	xb/=N;
	yb/=N;
	double xs=0;
	for(int i=0;i<N;i++)
	{
		xs+=(i-xb)*(i-xb);
	}
	xs/=N;
	double EXY=0;
	for(int i=0;i<N;i++)EXY+=i*A[i];
	EXY/=N;
	double Cov=EXY-xb*yb;
	double d=Cov/xs;
	double b=yb-d*xb;
	cout<<fixed<<setprecision(16);
	cout<<b<<" "<<d<<endl;
	double ans=0;
	for(int i=0;i<N;i++)
	{
		ans+=(A[i]-b-d*i)*(A[i]-b-d*i);
	}
	cout<<ans<<endl;
}