#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 5;

struct op {
    int ls, rs, mn, ct, lz;
} p[N << 5];

int cnt = 1;

int newNode(int l, int r) {
    int k = ++cnt;
    p[k].ls = p[k].rs = 0, p[k].mn = 0, p[k].ct = r - l + 1, p[k].lz = 0;
    return k;
}

void addTag(int k, int c) {
    p[k].mn += c, p[k].lz += c;
}

void pushdown(int k, int l, int r) {
    if (p[k].lz) {
        int mid = (l + r) >> 1;
        if (!p[k].ls) p[k].ls = newNode(l, mid);
        addTag(p[k].ls, p[k].lz);
        if (!p[k].rs) p[k].rs = newNode(mid + 1, r);
        addTag(p[k].rs, p[k].lz);
        p[k].lz = 0;
    }
}

void pushup(int k) {
    if (p[p[k].ls].mn == p[p[k].rs].mn) {
        p[k].mn = p[p[k].ls].mn, p[k].ct = p[p[k].ls].ct + p[p[k].rs].ct;
    } else {
        tie(p[k].mn, p[k].ct) = min(make_pair(p[p[k].ls].mn, p[p[k].ls].ct),
                                    make_pair(p[p[k].rs].mn, p[p[k].rs].ct));
    }
}

void modify(int &k, int l, int r, int x, int y, int c) {
    if (!k) {
        k = newNode(l, r);
    }
    if (l > y || r < x) return;
    if (l >= x && r <= y) {
        addTag(k, c);
        return;
    }
    pushdown(k, l, r);
    int mid = (l + r) >> 1;
    modify(p[k].ls, l, mid, x, y, c);
    modify(p[k].rs, mid + 1, r, x, y, c);
    pushup(k);
}

signed main() {
    int q, w, rt = 1; scanf("%d%d", &q, &w);
    map< pair<int, int>, int> M;
    p[1].ls = p[1].rs = 0, p[1].mn = 0, p[1].ct = w;
    while (q--) {
        int x, y, c; scanf("%d%d", &x, &y);
        if (M.count(make_pair(x, y))) {
            c = -1, M.erase(make_pair(x, y));
        } else {
            c = 1, M[make_pair(x, y)] = 1;
        }
        int L = max(x - y, 0), R = min(x + y - 1, w - 1);
        modify(rt, 0, w - 1, L, R, c);
        printf("%.10lf\n", (w - (p[1].mn != 0 ? 0 : p[1].ct)) * sqrt(2));
    }
    return 0;
}