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

const int N = 200009;
int a[N * 4];
int mn[N * 8], mn_cnt[N * 8], lz[N * 8];
pair <int, int> point[N];
pair <int, int> p[N];
map <int, int> m;

void calc(int v){
    if(mn[v * 2] < mn[v * 2 + 1]){
        mn[v] = mn[v * 2];
        mn_cnt[v] = mn_cnt[v * 2];
    } else if(mn[v * 2] > mn[v * 2 + 1]){
        mn[v] = mn[v * 2 + 1];
        mn_cnt[v] = mn_cnt[v * 2 + 1];
    } else {
        mn[v] = mn[v * 2];
        mn_cnt[v] = mn_cnt[v * 2] + mn_cnt[v * 2 + 1];
    }
}

void bld(int l, int r, int v){
    if(l == r){
        mn[v] = 0;
        mn_cnt[v] = a[l];
        return;
    }

    int mid = (l + r) / 2;
    bld(l, mid, v * 2);
    bld(mid + 1, r, v * 2 + 1);

    calc(v);
}

void pushdown(int l, int r, int v){
    if(l != r){
        lz[v * 2] += lz[v];
        lz[v * 2 + 1] += lz[v];
    }

    mn[v] += lz[v];
    lz[v] = 0;
}

void upd(int L, int R, int val, int l, int r, int v){
    pushdown(l, r, v);

    if(l > R || r < L) return;

    if(l >= L && r <= R){
        lz[v] = val;
        pushdown(l, r, v);
        return;
    }

    upd(L, R, val, l, (l + r) / 2, v * 2);
    upd(L, R, val, (l + r) / 2 + 1, r, v * 2 + 1);
    calc(v);
}

int main(){
    ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);
    int q, w;
    cin >> q >> w;

    vector <int> cut;
    cut.push_back(0);
    cut.push_back(w);
    for(int i = 1; i <= q; i++){
        cin >> point[i].first >> point[i].second;
        p[i] = {point[i].first - point[i].second, point[i].first + point[i].second};
        p[i].first = max(p[i].first, 0);
        p[i].second = min(p[i].second, w);

        cut.push_back(p[i].first);
        cut.push_back(p[i].second);
    }

    sort(cut.begin(), cut.end());

    int ind = 0;
    m[0] = 0;
    for(int i = 1; i < cut.size(); i++){
        if(cut[i] != cut[i - 1]){
            ind++;
            a[ind] = cut[i] - cut[i - 1];
            m[cut[i]] = ind;
        }
    }

    /*for(int i = 1; i <= ind; i++) cout << a[i] << " ";
    cout << "\n";*/

    int sz = 1;
    while(sz < ind) sz *= 2;

    bld(1, sz, 1);

    map <pair <int, int>, bool> mount;
    for(int i = 1; i <= q; i++){
        int l = m[p[i].first] + 1, r = m[p[i].second];
        //cout << l << " " << r << "\n";

        if(mount[point[i]]){
            mount[point[i]] = 0;
            upd(l, r, -1, 1, sz, 1);
        }else{
            mount[point[i]] = 1;
            upd(l, r, 1, 1, sz, 1);
        }

        int ans = 0;
        if(mn[1] != 0){
            ans = w;
        } else {
            ans = w - mn_cnt[1];
        }

        long double x = 2;
        cout << setprecision(12) << sqrt(x) * ans << "\n";
    }
    return 0;
}