#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(p) p.begin(),p.end()
#define rep(i,a,b) for(int i=(int)a;i<(int)b;i++)
const int mod=998244353;
using ld = long double;

int main(){
	int N;
	cin>>N;
	ld ans=1e9;
	ll H;
	cin>>H;
	vector<ll> X(N),Y(N);
	vector p(N,vector(2,vector<ll>(3)));
	rep(i,0,N){
		cin>>X[i]>>Y[i];
		rep(j,0,2){
			p[i][j][0]=X[i]*X[i];
			p[i][j][1]=X[i]*Y[i];
			p[i][j][2]=Y[i]*Y[i];
			Y[i]=Y[i]-H;
		}
		Y[i]+=2*H;
	}
	vector<int> order(N);
	rep(i,0,N) order[i]=i;
	sort(all(order),[&](int l,int r){
		return X[l]>X[r];
	});
	rep(i,0,N+2){
		ll A,B,C;
		if(i<N) A=H-2*Y[i],B=X[i]*2,C=-H*X[i];
		else if(i==N) A=1,B=0,C=0;
		else if(i==N+1) A=-1,B=0,C=0;
		vector<int> pos(N);
		vector<vector<ll>> q(2,vector<ll>(3));
		auto f=[&](int ind,int ud,int s)->void{
			rep(j,0,3) q[ud][j]+=s*p[ind][ud][j];
		};
		auto g=[&]()->ld{
			ld tmp=0;
			rep(j,0,2){
				tmp+=q[j][2];
				if(q[j][0]) tmp-=(ld)(q[j][1]*q[j][1])/(ld)(q[j][0]);
			}
			return tmp;
		};
		rep(j,0,N){
			if(A*X[j]+B*Y[j]+C>=0) pos[j]=1;
			else pos[j]=0;
			f(j,pos[j],1);
		}
		rep(j,0,N+1){
			ans=min(ans,g());
			if(j==N) break;
			int a=order[j];
			f(a,pos[a],-1);
			pos[a]=1-pos[a];
			f(a,pos[a],1);
		}
	}
	cout<<fixed<<setprecision(20)<<ans<<"\n";
}