#include <bits/stdc++.h>
using namespace std;
const int N = 2e6 + 10;
int tot, q, w, rt;
struct node { // 动态开点
    int lc, rc, sum, tag;
} t[N << 4];
void pushup(int x, int l, int r) {
    if(t[x].tag) {
        t[x].sum = r - l + 1;
    } else {
        t[x].sum = t[t[x].lc].sum + t[t[x].rc].sum;
    }
}
void modify(int &x, int l, int r, int L, int R, int v) {
    if(!x) x = ++tot;
    if(L <= l && r <= R) {
        t[x].tag += v;
        return pushup(x, l, r);
    }
    int mid = (l + r) / 2;
    if(L <= mid) modify(t[x].lc, l, mid, L, R, v);
    if(mid + 1 <= R) modify(t[x].rc, mid + 1, r, L, R, v);
    pushup(x, l, r);
}
map<pair<int, int>, int> mp;
int main() {
    cin >> q >> w;
    while(q --) {
        int x, y; cin >> x >> y;
        int f = (mp[{x, y}] == 1) ? (-1) : 1;
        modify(rt, 0, w, max(x - y, 0), min(x + y, w) - 1, f);
        printf("%.6lf\n", (double)t[rt].sum * (double)sqrt(2));
    }
    return 0;
}