#include <bits/stdc++.h>
#define ll long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pdd pair<double, double>
#define F first
#define S second
using namespace std;

ll N, Q, W;
int in[100005];
map<pll, int> mp;
multiset<ll> st[2];

signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> Q >> W;
    for (int i = 1; i <= Q; i++)
    {
        ll x, y;
        cin >> x >> y;
        if (mp.find(pll(x, y)) == mp.end())
            mp[pll(x, y)] = ++N;
        int j = mp[pll(x, y)];
        in[j] ^= 1;
        if (in[j])
        {
            st[0].insert(y - x);
            st[1].insert(y + x);
        }
        else 
        {
            st[0].erase(st[0].find(y - x));
            st[1].erase(st[1].find(y + x));  
        }
        if (st[0].empty())
        {
            cout << 0 << '\n';
            continue;
        }
        {
            double a = *st[0].rbegin(), b = *st[1].rbegin();
            double x = (b - a) / 2, y = (a + b) / 2;
            double l = max(0.0, x - y), r = min(double(W), x + y);
            cout << fixed << setprecision(10) << (r - l) * sqrtl(2) << '\n';
        }
    }

}