#include <bits/stdc++.h>
//#define int long long
#define fi first
#define se second 
#define pb push_back
#define ott(i, l, r) for (register int i = (l); i <= (r); i ++)
#define tto(i, l, r) for (register int i = (r); i >= (l); i --)
using namespace std;
typedef long long ll;
typedef long double ld;
int read () {
	int x = 0; bool f = false; char c = getchar ();
	while (!isdigit (c)) f |= (c == '-'), c = getchar ();
	while (isdigit (c)) x = (x << 3) + (x << 1) + (c ^ 48), c = getchar ();
	return f ? -x : x;
}
const int N = 2e5 + 110, mod = 1e9 + 7;
int n, m, q, w, res;
pair <int, int> a[N];
map <int, map <int, bool> > del;
int ta[N << 1], ts[N << 1];
struct Segment_Tree {
	pair <int, int> to[N << 2]; 
	set <int> lv[N]; bool rev;
	#define ls p << 1
	#define rs p << 1 | 1
	void pup (int p) {
		return void (to[p] = to[rs].fi ? to[rs] : to[ls]);
	}
	void add (int p, int l, int r, int x, int v) {
		if (l >= r) {
			if (v < 0) lv[l].erase (-v); else lv[l].insert (v); to[p].se = l;
			return void (to[p].fi = lv[l].empty () ? 0 : (rev ? *lv[l].rbegin () : *lv[l].begin ()));
		}
		int mid = l + r >> 1; 
		x <= mid ? add (ls, l, mid, x, v) : add (rs, mid + 1, r, x, v);
		return pup (p);
	}
} Ta, Ts;//R L
int main () {
	q = read (), w = read (), Ta.rev = false, Ts.rev = true;
	ott (i, 1, q) {
		int x = read (), y = read (); a[i].fi = x, a[i].se = y;
		ta[++ ta[0]] = y + x, ts[++ ts[0]] = y - x;
	}
	sort (ta + 1, ta + 1 + ta[0]), sort (ts + 1, ts + 1 + ts[0]);
	ott (i, 1, q) {
		int x = a[i].fi, y = a[i].se;
		int xa = lower_bound (ta + 1, ta + 1 + ta[0], y + x) - ta;
		int xs = lower_bound (ts + 1, ts + 1 + ts[0], y - x) - ts;
		if (del[x][y]) Ta.add (1, 1, ta[0], xa, -x), Ts.add (1, 1, ts[0], xs, -x);
		else Ta.add (1, 1, ta[0], xa, x), Ts.add (1, 1, ts[0], xs, x);
		del[x][y] ^= 1; pair <int, int> l = Ts.to[1], r = Ta.to[1];
		// printf ("[%d %d]\n", l.fi, r.fi);
		if (l.fi) {
			assert (l.fi <= r.fi);
			res = r.fi - l.fi + min (l.fi, ts[l.se] + l.fi) + min (w - r.fi, ta[r.se] - r.fi);
		} 
		//min (p[1].x, p[1].y)
		printf ("%.6lf\n", 1.0 * res * pow (2, 0.5)), res = 0;
	}
    return 0;
}