#include #include using namespace std; using i32 = int; using u32 = unsigned int; using i64 = long long; using u64 = unsigned long long; #define FAST_IO \ ios::sync_with_stdio(false); \ cin.tie(0); const i64 INF = 1001001001001001001; using Modint = atcoder::static_modint<998244353>; int N; double H; vector x, y; double L(double a1, double a2) { double ret = 0; for (int i = 0; i < N; i++) { double y1 = a1 * x[i] + H; double y2 = a2 * x[i]; ret += min(pow(y1 - y[i], 2), pow(y2 - y[i], 2)); } return ret; } double search(double mn1, double mx1, double mn2, double mx2, int iter) { double l = mn1, r = mx1; double b, t; double v1, v2; for (int i = 0; i < iter; i++) { double theta1 = (l * 2 + r) / 3; double theta2 = (l + r * 2) / 3; double a11 = tan(theta1); double a12 = tan(theta2); { b = mn2, t = mx2; for (int j = 0; j < iter; j++) { double phi1 = (b * 2 + t) / 3; double phi2 = (b + t * 2) / 3; double a21 = tan(phi1); double a22 = tan(phi2); if (L(a11, a21) < L(a11, a22)) { t = phi2; } else { b = phi1; } } v1 = L(a11, tan(b)); } { b = mn2, t = mx2; for (int j = 0; j < iter; j++) { double phi1 = (b * 2 + t) / 3; double phi2 = (b + t * 2) / 3; double a21 = tan(phi1); double a22 = tan(phi2); if (L(a12, a21) < L(a12, a22)) { t = phi2; } else { b = phi1; } } v2 = L(a12, tan(b)); } if (v1 < v2) { r = theta2; } else { l = theta1; } } return min(v1, v2); } int main() { FAST_IO cin >> N >> H; x.resize(N); y.resize(N); for (int i = 0; i < N; i++) { cin >> x[i] >> y[i]; } vector theta(N), phi(N); for (int i = 0; i < N; i++) { theta[i] = atan2(y[i] - H, x[i]); phi[i] = atan2(y[i], x[i]); } ranges::sort(theta); ranges::sort(phi); double ans = INF; for (int i = 0; i < N - 1; i++) { double mn1 = theta[i]; double mx1 = theta[i + 1]; for (int j = 0; j < N - 1; j++) { double mn2 = phi[j]; double mx2 = phi[j + 1]; auto v = search(mn1, mx1, mn2, mx2, 30); ans = min(ans, v); } } cout << fixed << setprecision(10) << ans << endl; }