#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); i++)
#define all(x) begin(x), end(x)
#define sz(x) int((x).size())
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;

#ifdef LOCAL
auto operator<<(auto& o, auto x) -> decltype(x.first, o);
auto operator<<(auto& o, auto x) -> decltype(x.end(), o) {
  o << "{";
  for (int i = 0; auto y : x) o << ", " + !i++ * 2 << y;
  return o << "}";
}
auto operator<<(auto& o, auto x) -> decltype(x.first, o) {
  return o << "(" << x.first << ", " << x.second << ")";
}
void __print(auto... x) { ((cerr << x << " "), ...) << endl; }
#define debug(x...) __print("[" #x "]:", x)
#else
#define debug(...) 2137
#endif

struct Node {
  int a, b;
  Node *nl = 0, *nr = 0;
  int mn, ile;
  int d = 0;
  Node(int aa, int bb) : a(aa), b(bb) {
    mn = 0;
    ile = b - a;
  }
  void app(int x) {
    mn += x;
    d += x;
  }
  void push() {
    int m = (a + b) / 2;
    if (!nl) nl = new Node(a, m);
    if (!nr) nr = new Node(m, b);
    if (d) {
      nl->app(d);
      nr->app(d);
      d = 0;
    }
  }
  void dod(int l, int r, int x) {
    if (l <= a && b <= r) {
      app(x);
      return;
    }
    if (b <= l || a >= r) return;
    push();
    nl->dod(l, r, x);
    nr->dod(l, r, x);
    mn = min(nl->mn, nr->mn);
    ile = (nl->mn == mn ? nl->ile : 0) + (nr->mn == mn ? nr->ile : 0);
  }
};

int main() {
  cin.tie(0)->sync_with_stdio(0);
  int q, w;
  cin >> q >> w;
  Node t(0, w);
  set<pii> s;
  cout << fixed << setprecision(9);
  while (q--) {
    int x, y;
    cin >> x >> y;
    int l = max(0, x - y);
    int r = min(w, x + y);
    if (s.count({x, y})) {
      s.erase({x, y});
      t.dod(l, r, -1);
    } else {
      s.insert({x, y});
      t.dod(l, r, 1);
    }
    cout << sqrt(2.0) * (w - (t.mn == 0 ? t.ile : 0)) << '\n';
  }
}