#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> using namespace std; using namespace __gnu_pbds; #define inf (ll)1e15 #define ll long long #define lll __int128_t #define pi pair<int, int> #define pl pair<ll, ll> #define vi vector<int> #define vl vector<ll> #define vd vector<double> #define mod 1000000007 // #define mod 998244353 #define pie acos(-1.0) #define LSOne(i) ((i) & -(i)) #define EPS 1e-9 struct point{ double x, y; }; double dist(point a, point b){ return sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y)); } double val(vector<point> &vtr, double x){ double ans = -inf; for(point p : vtr){ ans = max(ans, dist({x, 0}, p)); } return ans; } int main(){ std::ios::sync_with_stdio(false); cin.tie(nullptr); ll n, m; cin >> n >> m; vector<point> vtr(n); for(ll i = 0; i < n; i++) cin >> vtr[i].x >> vtr[i].y; double lo = 0, hi = m, ans; for(int i = 0; i <= 50; i++){ double m1 = lo + (hi-lo)/3; double m2 = hi - (hi-lo)/3; double val1 = val(vtr, m1); double val2 = val(vtr, m2); if(val1 <= val2){ hi = m2, ans = val1; } else{ lo = m1, ans = val2; } } cout << fixed << setprecision(5) << ans << "\n"; }