#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; }; bool feasible(vector<point> &vtr, double r, double m){ double cover = 0; for(auto [x, y] : vtr){ double lo_x = x - sqrt(r*r - y*y); double hi_x = x + sqrt(r*r - y*y); if(lo_x <= cover) cover = max(cover, hi_x); } return cover >= m; } 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; for(int i = 0; i <= 25; i++){ double mid((lo+hi)/2); feasible(vtr, mid, m) ? hi = mid : lo = mid; } cout << fixed << setprecision(5) << (hi+lo)/2 << "\n"; }