#include <bits/stdc++.h>
using namespace std;
bool debug = 0;
int n, m, k;
int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
string direc = "RDLU";
long long ln, lk, lm;
void etp(bool f = 0) {
  puts(f ? "YES" : "NO");
  exit(0);
}
void addmod(int& x, int y, int mod = 1000000007) {
  x += y;
  if (x >= mod) x -= mod;
}
void et() {
  puts("-1");
  exit(0);
}
struct Point {
  long double x, y, r;
  Point() {}
  Point(long double x, long double y) : x(x), y(y) {}
  long double abs() const { return hypot(x, y); }
  long double arg() const { return atan2(y, x); }
  Point operator*(long double o) const { return Point(x * o, y * o); }
  Point operator+(const Point& o) const { return Point(x + o.x, y + o.y); }
  Point operator-(const Point& o) const { return Point(x - o.x, y - o.y); }
  bool operator<(const Point& o) const {
    return x < o.x - 1e-9 || (x < o.x + 1e-9 && y < o.y - 1e-9);
  }
  Point scale(long double o) const { return *this * (o / abs()); }
  Point rotY() const { return Point(-y, x); }
  Point rotX() const { return Point(y, -x); }
  long double cross(Point b) const { return x * b.y - b.x * y; }
  long double dot(Point b) const { return x * b.x + y * b.y; }
  long double disToSeg(Point& a, Point& b) {
    return fabs(((*this) - a).cross(b - a) / (b - a).abs());
  }
  void readin() { scanf("%Lf%Lf", &x, &y); }
};
Point p[100005], Q;
int A;
long double gg(long double t) {
  if (t < -acos(-1)) t += acos(-1) * 2;
  if (t > acos(-1)) t -= acos(-1) * 2;
  return t;
}
bool ck(long double R) {
  vector<pair<long double, int>> vp;
  for (int(i) = 1; (i) <= (int)(n); (i)++) {
    long double a = p[i].r, b = R, c = p[i].abs();
    if (a + b <= c || abs(a - b) >= c) continue;
    long double cosThe = (b * b + c * c - a * a) / 2 / b / c;
    long double the = acos(cosThe);
    long double tmp = p[i].arg();
    long double x = gg(tmp + the), y = gg(tmp - the);
    vp.push_back({min(x, y), -i});
    vp.push_back({max(x, y), i});
  }
  sort(vp.begin(), vp.end());
  int N = vp.size();
  vector<int> v;
  for (int(i) = 0; (i) < (int)(N); (i)++) {
    if (vp[i].second < 0)
      v.push_back(-vp[i].second);
    else {
      if (v.back() != vp[i].second) {
        return 1;
      }
      v.pop_back();
    }
  }
  return 0;
}
void fmain() {
  scanf("%d%d", &n, &A);
  Q = Point(A + A, 0);
  for (int(i) = 1; (i) <= (int)(n); (i)++) {
    p[i].readin();
    p[i].x += A;
    p[i].r = (p[i] - Q).abs();
  }
  long double l = 0, r = A + A;
  while (abs(l - r) > 1e-9) {
    long double mid = (l + r) / 2;
    if (ck(mid))
      r = mid;
    else
      l = mid;
  }
  printf("%.10Lf\n", l);
}
int main() {
  fmain();
  return 0;
}
