#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
template <typename T, typename U> inline bool chmin(T &x, U y) { return (y < x) ? (x = y, true) : false; }

int main(){
    ll n, h; cin >> n >> h;
    vector<pair<ll,ll>> xys(n);
    for (int i = 0; i < n; i++) cin >> xys[i].first >> xys[i].second;
    sort(xys.begin(),xys.end());
    ld ans = 1e18;
    for (int i = 0; i < n; i++){
        vector<int> uls(n,0); // 0 : lower, 1 : upper
        auto [xi, yi] = xys[i];
        for (int j = 0; j < n; j++){
            auto [xj, yj] = xys[j];
            if ((2*yi-h)*xj + h*xi <= 2*xi*yj) uls[j] = 1;
        }
        array<ll,3> lv = {0,0,0}, uv = {0,0,0};
        auto uadd = [&](int j, ll add_del){
            auto [xj, yj] = xys[j];
            uv[0] += add_del * (h-yj)*(h-yj);
            uv[1] += add_del * 2*xj*(h-yj);
            uv[2] += add_del * xj*xj;
        };
        auto ladd = [&](int j, ll add_del){
            auto [xj, yj] = xys[j];
            lv[0] += add_del * (-yj)*(-yj);
            lv[1] += add_del * 2*xj*(-yj);
            lv[2] += add_del * xj*xj;
        };
        for (int j = 0; j < n; j++){
            if (uls[j] == 0){
                ladd(j,+1);
            }
            else {
                uadd(j,+1);
            }
        }
        auto eval = [](array<ll,3> ar){
            auto [a0, a1, a2] = ar;
            if (a2 == 0) return ld(0);
            ld ans = a0;
            ans -= ld(a1)*a1/(4*a2);
            return ans;
        };
        chmin(ans,eval(lv)+eval(uv));
        for (int j = n-1; j >= 0; j--){
            if (uls[j] == 0){
                ladd(j,-1);
                uadd(j,+1);
            }
            else {
                uadd(j,-1);
                ladd(j,+1);
            }
            chmin(ans,eval(lv)+eval(uv));
        }
    }
    cout << fixed << setprecision(15) << ans << endl;
}