#include <bits/stdc++.h>
using namespace std;
#define rep(i,l,r) for (int i = (l); i <= (r); i++)
#define per(i,r,l) for (int i = (r); i >= (l); i--)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
#define maxn(a, b) a = max(a, b)
#define minn(a, b) a = min(a, b)
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
const ll mod = 998244353;
mt19937 gen(random_device{}());
ll rp(ll a,ll b) {ll res=1%mod;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}

const int inf = 1e9;
const int N = 200010;

struct info {
    int mn, cnt, lz;
    info(): mn(0), cnt(0), lz(0){}
    friend info operator + (const info &x, const info &y) {
        info z;
        z.mn = min(x.mn, y.mn);
        z.cnt = 0;
        if (x.mn == z.mn) z.cnt += x.cnt;
        if (y.mn == z.mn) z.cnt += y.cnt;
        return z;
    }
};

int idx;
int ls[N*60], rs[N*60];
info s[N*60];

void getnew(int &x, int sz) {
    if (x) return ;
    x = ++idx;
    s[x].cnt = sz;
}

void pushdown(int id) {
    if (s[id].lz) {
        s[ls[id]].mn += s[id].lz;
        s[rs[id]].mn += s[id].lz;
        s[ls[id]].lz += s[id].lz;
        s[rs[id]].lz += s[id].lz;
        s[id].lz = 0;
    }
}

void change(int id, int l, int r, int x, int y, int c) {
    if (x <= l && r <= y) {
        s[id].lz += c;
        s[id].mn += c;
        return ;
    }
    int mid = (l + r) >> 1;
    getnew(ls[id], mid - l + 1);
    getnew(rs[id], r - mid);
    pushdown(id);
    if (x <= mid) change(ls[id], l, mid, x, y, c);
    if (y > mid) change(rs[id], mid + 1, r, x, y, c);
    s[id] = s[ls[id]] + s[rs[id]];
}

info query(int id, int l, int r, int x, int y) {
    if (x <= l && r <= y) {
        return s[id];
    }
    int mid = (l + r) >> 1;
    getnew(ls[id], mid - l + 1);
    getnew(rs[id], r - mid);
    pushdown(id);
    info res;
    if (x <= mid) res = res + query(ls[id], l, mid, x, y);
    if (y > mid) res = res + query(rs[id], mid + 1, r, x, y);
    return res;
}

int main() {
    int q, w;
    scanf("%d%d", &q, &w);
    set<PII> st;
    int rt = 0;
    getnew(rt, w);

    while (q--) {
        int x, y;
        scanf("%d%d", &x, &y);
        int l = x - y, r = x + y;
        maxn(l, 0);
        minn(r, w);
        if (st.count(mp(x, y))) {
            change(rt, 1, w, l + 1, r, -1);
            st.erase(mp(x, y));
        } else {
            // printf("%d %d +1\n", l, r);
            change(rt, 1, w, l + 1, r, 1);
            st.insert(mp(x, y));
        }
        // printf("%d %d %d %d\n", l, r, s[1].cnt, s[1].mn);
        printf("%.6lf\n", (w - s[1].cnt) * sqrt(2));
    }
    return 0;
}