#include <bits/stdc++.h>
#define _rep(i, x, y) for(int i = x; i <= y; ++i)
#define _req(i, x, y) for(int i = x; i >= y; --i)
#define _rev(i, u) for(int i = head[u]; i; i = e[i].nxt)
#define pb push_back
#define fi first
#define se second
#define mst(f, i) memset(f, i, sizeof f)
using namespace std;
#ifdef ONLINE_JUDGE
#define debug(...) 0
#else
#define debug(...) fprintf(stderr, __VA_ARGS__), fflush(stderr)
#endif
typedef long long ll;
typedef pair<int, int> PII;
namespace fastio{
    #ifdef ONLINE_JUDGE
    char ibuf[1 << 20],*p1 = ibuf, *p2 = ibuf;
    #define get() p1 == p2 && (p2 = (p1 = ibuf) + fread(ibuf, 1, 1 << 20, stdin), p1 == p2) ? EOF : *p1++
    #else
    #define get() getchar()
    #endif
    template<typename T> inline void read(T &t){
        T x = 0, f = 1;
        char c = getchar();
        while(!isdigit(c)){
            if(c == '-') f = -f;
            c = getchar();
        }
        while(isdigit(c)) x = x * 10 + c - '0', c = getchar();
        t = x * f;
    }
    template<typename T, typename ... Args> inline void read(T &t, Args&... args){
        read(t);
        read(args...);
    }
    template<typename T> void write(T t){
        if(t < 0) putchar('-'), t = -t;
        if(t >= 10) write(t / 10);
        putchar(t % 10 + '0');
    }
    template<typename T, typename ... Args> void write(T t, Args... args){
        write(t), putchar(' '), write(args...);
    }
    template<typename T> void writeln(T t){
        write(t);
        puts("");
    }
    template<typename T> void writes(T t){
        write(t), putchar(' ');
    }
    #undef get
};
using namespace fastio;
#define multitest() int T; read(T); _rep(tCase, 1, T)
namespace Calculation{
    const ll mod = 998244353;
    ll ksm(ll p, ll h){ll base = p % mod, res = 1; while(h){if(h & 1ll) res = res * base % mod; base = base * base % mod, h >>= 1ll;} return res;}
    void dec(ll &x, ll y){x = ((x - y) % mod + mod) % mod;}
    void add(ll &x, ll y){x = (x + y) % mod;}
    void mul(ll &x, ll y){x = x * y % mod;}
    ll sub(ll x, ll y){return ((x - y) % mod + mod) % mod;}
    ll pls(ll x, ll y){return ((x + y) % mod + mod) % mod;}
    ll mult(ll x, ll y){return x * y % mod;}
}
using namespace Calculation;
const int N = 2e5 + 5;
typedef long double lb;
int q;
lb w;
map<PII, bool> vis;
multiset<int> L, R;
void ins(int x, int y){
    L.insert(x - y), R.insert(x + y);
}
void del(int x, int y){
    L.erase(L.find(x - y)), R.erase(R.find(x + y));
}
struct node{
    lb x, y;
    node(lb _x = 0, lb _y = 0){x = _x, y = _y;}
    node operator+(const node b)const{return node(x + b.x, y + b.y);}
    node operator-(const node b)const{return node(x - b.x, y - b.y);}
    lb len(){return sqrtl(x * x + y * y);}
};
lb calc(){
    if(L.empty()) return 0;
    lb x0 = *L.begin(), x1 = *prev(R.end());
    lb tx = (x0 + x1) / 2.00, ty = tx - x0;
    node u = node(x0, 0), v = node(x1, 0), cur = node(tx, ty);
    lb ans = 0;
    if(cur.x > 0){
        if(u.x < 0) ans += (cur - node(0, -x0)).len();
        else ans += (cur - u).len();
    }
    if(cur.x < w){
        if(v.x > w) ans += (cur - node(w, -w + x1)).len();
        else ans += (cur - v).len();
    }
    return ans;
}
int main(){
    read(q), scanf("%Lf", &w);
    while(q--){
        int x, y; read(x, y);
        if(vis[{x, y}]) del(x, y), vis[{x, y}] = 0;
        else ins(x, y), vis[{x, y}] = 1;
        printf("%.10Lf\n", calc());
    } 
    return 0;
}