// Source: https://usaco.guide/general/io #include <bits/stdc++.h> using namespace std; using ll = long long; using ld = long double; vector<pair<ld,ld>> points; ld f(ld m){ ld val = 1e18; for (auto point: points){ val = min(val, (m-point.first)*(m-point.first) + point.second*point.second); } return val; } int main() { ios::sync_with_stdio(0); cin.tie(0); ld n, L; cin >> n >> L; points.resize(n); for (ll i{}; i < n; i++){ ld x, y; cin >> x >> y; points[i] = {x,y}; } ld l = 0, r = L, eps = 1e-9; while (r-l > eps){ ld m1 = l + (r-l)/3; ld m2 = r - (r-l)/3; ld f1 = f(m1); ld f2 = f(m2); if (f2 > f1) l = m1; else r = m2; } cout << fixed << setprecision(6) << sqrt(f(l)); }