#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using LL = long long;
using pii = pair<int, int>;
#define sz(x) (signed)size(x)

struct segTree {
    int l, r, mid;
    int mn = 0, cnt = 0, tag = 0;
    segTree *lson = nullptr, *rson = nullptr;

    segTree (int _l, int _r) : l(_l), r(_r), mid((l + r) >> 1), cnt(r - l) {}

    void push() {
        for (segTree* son : {lson, rson}) {
            son->mn += tag;
            son->tag += tag;
        }
        tag = 0;
    }

    void pull() {
        mn = min(lson->mn, rson->mn);
        if (lson->mn < rson->mn)
            cnt = lson->cnt;
        else if (lson->mn > rson->mn)
            cnt = rson->cnt;
        else
            cnt = lson->cnt + rson->cnt;
    }

    void add(int ql, int qr, int val) {
        if (l == ql && r == qr) {
            mn += val;
            tag = val;
            return;
        }

        if (lson == nullptr)
            lson = new segTree(l, mid);
        if (rson == nullptr)
            rson = new segTree(mid, r);

        push();

        if (qr <= mid) {
            lson->add(ql, qr, val);
        }
        else if (mid <= ql) {
            rson->add(ql, qr, val);
        }
        else {
            lson->add(ql, mid, val);
            rson->add(mid, qr, val);
        }


        pull();
    }
};

void solve () {
    int q, w;
    cin >> q >> w;

    set<pii> st;
    segTree* root = new segTree(0, w);
    while (q--) {
        int x, y;
        cin >> x >> y;
        int l = max(0, x - y), r = min(w, x + y);

        if (st.count({x, y})) {
            root->add(l, r, -1);
            st.erase({x, y});
        }
        else {
            root->add(l, r, 1);
            st.emplace(x, y);
        }

        int tmp = w;
        if (root->mn == 0)
            tmp -= root->cnt;
        cout << fixed << setprecision(10) << sqrtl(2) * tmp << '\n';
    }
}

signed main() {
    cin.tie(0)->sync_with_stdio(0);

    solve();
}