use std::collections::*;
use std::io::Write;

type Map<K, V> = BTreeMap<K, V>;
type Set<T> = BTreeSet<T>;
type Deque<T> = VecDeque<T>;

fn run() {
    input! {
        q: usize,
        w: i32,
        ask: [(i32, i32); q],
    }
    let mut z = vec![];
    z.extend(ask.iter().map(|p| p.0 + p.1));
    z.extend(ask.iter().map(|p| p.0 - p.1));
    z.push(0);
    z.push(w);
    z.retain(|p| 0 <= *p && *p <= w);
    z.sort();
    z.dedup();
    let width = z.windows(2).map(|z| z[1] - z[0]).collect::<Vec<_>>();
    let mut seg = LazySegmentTree::build(width.iter().map(|w| (0, *w)), width.len(), R);
    let out = std::io::stdout();
    let mut out = std::io::BufWriter::new(out.lock());
    let mut set = Set::new();
    for (x, y) in ask {
        let l = z.binary_search(&(x - y).max(0)).unwrap();
        let r = z.binary_search(&(x + y).min(w)).unwrap();
        if set.insert((x, y)) {
            seg.update(l, r, 1);
        } else {
            set.remove(&(x, y));
            seg.update(l, r, -1);
        }
        let mut ans = w;
        let p = seg.find(0, width.len());
        if p.0 == 0 {
            ans -= p.1;
        }
        writeln!(out, "{:.7}", ans as f64 * 2f64.sqrt()).ok();
    }
}

struct R;
impl TE for R {
    type T = (i32, i32);
    type E = i32;
    fn fold(&self, l: &Self::T, r: &Self::T) -> Self::T {
        if l.0 == r.0 {
            (l.0, l.1 + r.1)
        } else {
            std::cmp::min(*l, *r)
        }
    }
    fn eval(&self, x: &Self::T, f: &Self::E) -> Self::T {
        (x.0 + *f, x.1)
    }
    fn merge(&self, g: &Self::E, h: &Self::E) -> Self::E {
        *g + *h
    }
    fn e(&self) -> Self::T {
        (std::i32::MAX / 2, 0)
    }
    fn id(&self) -> Self::E {
        0
    }
}

fn main() {
    run();
}

// ---------- begin input macro ----------
// reference: https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
#[macro_export]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
    ($($r:tt)*) => {
        let s = {
            use std::io::Read;
            let mut s = String::new();
            std::io::stdin().read_to_string(&mut s).unwrap();
            s
        };
        let mut iter = s.split_whitespace();
        input_inner!{iter, $($r)*}
    };
}

#[macro_export]
macro_rules! input_inner {
    ($iter:expr) => {};
    ($iter:expr, ) => {};
    ($iter:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($iter, $t);
        input_inner!{$iter $($r)*}
    };
}

#[macro_export]
macro_rules! read_value {
    ($iter:expr, ( $($t:tt),* )) => {
        ( $(read_value!($iter, $t)),* )
    };
    ($iter:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($iter, $t)).collect::<Vec<_>>()
    };
    ($iter:expr, chars) => {
        read_value!($iter, String).chars().collect::<Vec<char>>()
    };
    ($iter:expr, bytes) => {
        read_value!($iter, String).bytes().collect::<Vec<u8>>()
    };
    ($iter:expr, usize1) => {
        read_value!($iter, usize) - 1
    };
    ($iter:expr, $t:ty) => {
        $iter.next().unwrap().parse::<$t>().expect("Parse error")
    };
}
// ---------- end input macro ----------
// ---------- begin Lazy Segment Tree ----------
pub trait TE {
    type T: Clone;
    type E: Clone;
    fn fold(&self, l: &Self::T, r: &Self::T) -> Self::T;
    fn eval(&self, x: &Self::T, f: &Self::E) -> Self::T;
    fn merge(&self, g: &Self::E, h: &Self::E) -> Self::E;
    fn e(&self) -> Self::T;
    fn id(&self) -> Self::E;
}

pub struct LazySegmentTree<R: TE> {
    n: usize,
    size: usize,
    bit: u32,
    op: R,
    data: Vec<(R::T, R::E)>,
}

impl<R: TE> LazySegmentTree<R> {
    pub fn new(n: usize, op: R) -> Self {
        assert!(n > 0);
        let size = n.next_power_of_two();
        let bit = size.trailing_zeros();
        let data = vec![(op.e(), op.id()); 2 * size];
        Self {
            n,
            size,
            bit,
            op,
            data,
        }
    }
    pub fn build<I>(init: I, n: usize, op: R) -> Self
    where
        I: Iterator<Item = R::T>,
    {
        let mut seg = Self::new(n, op);
        for (data, ini) in seg.data[seg.size..].iter_mut().zip(init) {
            data.0 = ini;
        }
        for i in (1..seg.size).rev() {
            seg.pull(i);
        }
        seg
    }
    pub fn update(&mut self, l: usize, r: usize, f: R::E) {
        assert!(l <= r && r <= self.n);
        if l == r {
            return;
        }
        self.push_range(l, r);
        let mut s = l + self.size;
        let mut t = r + self.size;
        while s < t {
            if s & 1 == 1 {
                self.apply(s, &f);
                s += 1;
            }
            if t & 1 == 1 {
                t -= 1;
                self.apply(t, &f);
            }
            s >>= 1;
            t >>= 1;
        }
        let l = l + self.size;
        let r = r + self.size;
        for k in 1..=self.bit {
            if (l >> k) << k != l {
                self.pull(l >> k);
            }
            if (r >> k) << k != r {
                self.pull((r - 1) >> k);
            }
        }
    }
    pub fn find(&mut self, l: usize, r: usize) -> R::T {
        assert!(l <= r && r <= self.n);
        if l == r {
            return self.op.e();
        }
        self.push_range(l, r);
        let mut l = l + self.size;
        let mut r = r + self.size;
        let mut p = self.op.e();
        let mut q = self.op.e();
        while l < r {
            if l & 1 == 1 {
                p = self.op.fold(&p, &self.data[l].0);
                l += 1;
            }
            if r & 1 == 1 {
                r -= 1;
                q = self.op.fold(&self.data[r].0, &q);
            }
            l >>= 1;
            r >>= 1;
        }
        self.op.fold(&p, &q)
    }
    pub fn set_at(&mut self, x: usize, v: R::T) {
        assert!(x < self.n);
        let x = x + self.size;
        for k in (1..=self.bit).rev() {
            self.push(x >> k);
        }
        self.data[x].0 = v;
        for k in 1..=self.bit {
            self.pull(x >> k);
        }
    }
    fn push_range(&mut self, l: usize, r: usize) {
        let l = l + self.size;
        let r = r + self.size;
        for k in (1..(self.bit + 1)).rev() {
            if (l >> k) << k != l {
                self.push(l >> k);
            }
            if (r >> k) << k != r {
                self.push((r - 1) >> k);
            }
        }
    }
    fn apply(&mut self, x: usize, f: &R::E) {
        self.data[x].0 = self.op.eval(&self.data[x].0, f);
        self.data[x].1 = self.op.merge(&self.data[x].1, f);
    }
    fn push(&mut self, x: usize) {
        let f = std::mem::replace(&mut self.data[x].1, self.op.id());
        self.apply(2 * x, &f);
        self.apply(2 * x + 1, &f);
    }
    fn pull(&mut self, x: usize) {
        self.data[x].0 = self.op.fold(&self.data[2 * x].0, &self.data[2 * x + 1].0);
    }
}
// ---------- end Lazy Segment Tree ----------