#include <bits/stdc++.h>
using namespace std;

const int N = 2e5 + 10;
const double r2 = sqrt(2);
using peak = pair<int, int>;

struct node{
    peak l, r;
    double ans;
} tr[N * 33];

int sons[N * 33][2], tcnt = 1;

map<int, set<int> > mp;

node merge(const node &l, const node &r) {
    if(l.l.second == 0) return r;
    if(r.l.second == 0) return l;
    if(r.l.second - r.l.first >= l.l.second - l.l.first) return r;
    if(l.r.first + l.r.second >= r.r.first + r.r.second) return l;
    return node{l.l, r.r, l.ans + r.ans + r2 * abs(l.r.first - r.l.first)};
}

void modify(int u, int p, int x, int lvl) {
    if(lvl == -1) {
        tr[u].l = tr[u].r = x ? peak{p, x} : peak{0, 0};
        tr[u].ans = 0;
        return;
    }
    int v = (p >> lvl) & 1;
    if(!sons[u][v]) sons[u][v] = ++tcnt;
    modify(sons[u][v], p, x, lvl - 1);
    tr[u] = merge(tr[sons[u][0]], tr[sons[u][1]]);
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int q, w;
    cin >> q >> w;

    cout << fixed << setprecision(7);

    for(int i = 1, x, y; i <= q; i ++) {
        cin >> x >> y;
        if(mp[x].count(y)) mp[x].erase(y);
        else mp[x].insert(y);
        modify(1, x, mp[x].size() ? *mp[x].rbegin() : 0, 29);
        cout << (tr[1].l.second ? tr[1].ans + (min(tr[1].l.first, tr[1].l.second) + min(w - tr[1].r.first, tr[1].r.second)) * r2 : 0.0) << "\n";
    }
}