#include <bits/stdc++.h>

using namespace std;

#define iter(v) v.begin(), v.end()
#define SZ(v) int(v.size())
#define pb emplace_back
#define ff first
#define ss second

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

#ifdef zisk
void debug(){cerr << "\n";}
template<class T, class ... U>
void debug(T a, U ... b){ cerr << a << " ", debug(b...); }
template<class T> void pary(T l, T r){
	while(l != r) cerr << *l << " ", l++;
	cerr << "\n";
}
#else
#define debug(...) void()
#define pary(...) void()
#endif

template<class A, class B>
ostream& operator<<(ostream& o, pair<A, B> p){
	return o << '(' << p.ff << ',' << p.ss << ')';
}

struct Node{
	int mn = 0, cnt = 0, tag = 0, lc = -1, rc = -1;
};
int W;
struct SegTree{
	vector<Node> seg;
	int cur = 1;
	explicit SegTree(): seg(3e7) {
		seg[0].cnt = W;
	}
	int new_node(int L, int R){
		int id = cur++;
		seg[id].cnt = R - L + 1;
		return id;
	}
	void addtag(int v, int id){
		seg[id].mn += v;
		seg[id].tag += v;
	}
	void push(int L, int R, int id){
		int M = (L + R) / 2;
		if(seg[id].lc == -1) seg[id].lc = new_node(L, M);
		if(seg[id].rc == -1) seg[id].rc = new_node(M + 1, R);
		addtag(seg[id].tag, seg[id].lc);
		addtag(seg[id].tag, seg[id].rc);
		seg[id].tag = 0;
	}
	void pull(int id){
		seg[id].mn = min(seg[seg[id].lc].mn, seg[seg[id].rc].mn);
		seg[id].cnt = 0;
		if(seg[seg[id].lc].mn == seg[id].mn) seg[id].cnt += seg[seg[id].lc].cnt;
		if(seg[seg[id].rc].mn == seg[id].mn) seg[id].cnt += seg[seg[id].rc].cnt;
	}
	void modify(int l, int r, int v, int L = 0, int R = W - 1, int id = 0){
		if(l <= L && R <= r){
			addtag(v, id);
			//debug("ok modify", L, R, id, ":", seg[id].mn, seg[id].cnt);
			return;
		}
		//debug("modify", L, R, id);
		int M = (L + R) / 2;
		push(L, R, id);
		if(r <= M) modify(l, r, v, L, M, seg[id].lc);
		else if(l > M) modify(l, r, v, M + 1, R, seg[id].rc);
		else{
			modify(l, r, v, L, M, seg[id].lc);
			modify(l, r, v, M + 1, R, seg[id].rc);
		}
		pull(id);
		//debug("ok modify", L, R, id, ":", seg[id].mn, seg[id].cnt);
	}
	int count0(){
		return seg[0].mn == 0 ? seg[0].cnt : 0;
	}
};

using ld = long double;
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cerr.tie(0);
	
	int q;
	cin >> q;
	cin >> W;
	
	SegTree seg;

	set<pii> tmp;
	for(int i = 1; i <= q; i++){
		int x, y;
		cin >> x >> y;
		//debug("test", i, x - y, x + y - 1);
		if(tmp.find(pii(x, y)) == tmp.end()){
			seg.modify(x - y, x + y - 1, 1);
			tmp.insert(pii(x, y));
		}
		else{
			seg.modify(x - y, x + y - 1, -1);
			tmp.erase(pii(x, y));
		}
		ld ans = W - seg.count0();
		//debug("len", ans);
		ans *= sqrt(2);
		cout << fixed << setprecision(20) << ans << "\n";
	}

}