#include <bits/stdc++.h>

using namespace std;

using ll = long long;

class scan_line {
  public:
    vector<ll> val, len;
    ll n;

    scan_line(ll t) {
      n = t;
      val.resize(4 * n);
      len.resize(4 * n);
    }

    void modify(ll l, ll r, ll t, ll p, ll tl, ll tr) {
      if (r < tl || l > tr) return;
      ll mid = (tl + tr) >> 1;
      if (l <= tl && r >= tr) val[p] += t;
      else {
        modify(l, r, t, p << 1, tl, mid);
        modify(l, r, t, p << 1 | 1, mid + 1, tr);
      }
      if (val[p]) len[p] = tr - tl + 1;
      else if (tl == tr) len[p] = 0;
			else len[p] = len[p << 1] + len[p << 1 | 1];
    }

    void modify(ll l, ll r, ll t) {
      if (r >= l) modify(l, r, t, 1, 1, n);
    }

    ll slen() {
      return len[1];
    }
};

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);

	int q, w;
	cin >> q >> w;
	set<pair<int, int>> s;
	
	scan_line sc(w);
	
	while (q--) {
		int x, y;
		cin >> x >> y;
		
		const int l = max(0, x - y), r = min(w, x + y);
		
		if (s.find({x, y}) == s.end()) {
			s.insert({x, y});
			sc.modify(l + 1, r, 1);
		} else {
			sc.modify(l + 1, r, -1);
		}
		
		cout << setprecision(15) << __builtin_sqrtl(2) * (double)sc.slen() << '\n';
	}

  return 0;
}