Problem:
Score: 500 points

Problem Statement

We have caught N sardines. The deliciousness and fragrantness of the i-th sardine is A_i and B_i, respectively.

We will choose one or more of these sardines and put them into a cooler. However, two sardines on bad terms cannot be chosen at the same time.

The i-th and j-th sardines (i \neq j) are on bad terms if and only if A_i \cdot A_j + B_i \cdot B_j = 0.

In how many ways can we choose the set of sardines to put into the cooler? Since the count can be enormous, print it modulo 1000000007.

Constraints

All values in input are integers.

1 \leq N \leq 2 \times 10^5

-10^{18} \leq A_i, B_i \leq 10^{18}

Input

Input is given from Standard Input in the following format:

N
A_1 B_1
:
A_N B_N

Output

Print the count modulo 1000000007.

Sample Input 1

3
1 2
-1 1
2 -1

Sample Output 1

5

There are five ways to choose the set of sardines, as follows:

The 1-st

The 1-st and 2-nd

The 2-nd

The 2-nd and 3-rd

The 3-rd

Sample Input 2

10
3 2
3 2
-1 1
2 -1
-3 -9
-8 12
7 7
8 1
8 2
8 4

Sample Output 2

479

Solution in Rust (1.42.0) (judge verdict: Accepted)

#![allow(unused_imports, unused_macros)]

use kyoproio::*;
use std::{
    collections::*,
    io::{self, prelude::*},
    iter,
    mem::{replace, swap},
};

fn main() -> io::Result<()> {
    std::thread::Builder::new()
        .stack_size(64 * 1024 * 1024)
        .spawn(solve)?
        .join()
        .unwrap();
    Ok(())
}

fn solve() {
    let stdin = io::stdin();
    let mut kin = KInput::new(stdin.lock());
    let stdout = io::stdout();
    let mut out = io::BufWriter::new(stdout.lock());
    macro_rules! output { ($($args:expr),+) => { write!(&mut out, $($args),+).unwrap(); }; }
    macro_rules! outputln {
        ($($args:expr),+) => { output!($($args),+); outputln!(); };
        () => { output!("\n"); if cfg!(debug_assertions) { out.flush().unwrap(); } }
    }

    const MOD: i64 = 1e9 as i64 + 7;
    let n: usize = kin.input();
    let mut map = BTreeMap::new();
    let mut zero = 0;
    for (a, b) in kin.iter::<(i64, i64)>().take(n) {
        if a == 0 && b == 0 {
            zero += 1;
        } else {
            let r = if b == 0 {
                Rational::new(-1, 0)
            } else {
                Rational::new(a, b)
            };
            *map.entry(r).or_insert(0) += 1;
        }
    }

    let mut ans = 1;
    let mut set = BTreeSet::new();
    for (&r, &v) in map.iter() {
        if set.contains(&r) {
            continue;
        }
        let ir = -r.inv();
        let iv = map.get(&ir).cloned().unwrap_or(0);
        ans = ans * (mod_pow(2, v, MOD) + mod_pow(2, iv, MOD) - 1) % MOD;
        set.insert(ir);
    }

    ans = (ans + zero - 1).rem_euclid(MOD);
    outputln!("{}", ans);
}

pub fn mod_pow(mut a: i64, mut b: i64, m: i64) -> i64 {
    let mut y = 1;
    while b > 0 {
        if b & 1 == 1 {
            y = y * a % m;
        }
        a = a * a % m;
        b >>= 1;
    }
    y
}

#[repr(C)]
#[derive(Clone, Copy, Default, PartialEq, Eq, Debug)]
pub struct Rational(i64, i64);
impl Rational {
    pub fn new(nom: i64, den: i64) -> Self {
        Self(nom, den).reduced()
    }
    pub fn inv(self) -> Self {
        if self.0 >= 0 {
            Self(self.1, self.0)
        } else {
            Self(-self.1, -self.0)
        }
    }
    fn reduced(self) -> Self {
        let Self(nom, den) = self;
        let d = gcd(nom.abs(), den.abs());
        if den >= 0 {
            Self(nom / d, den / d)
        } else {
            Self(-nom / d, -den / d)
        }
        .checked()
    }
    fn checked(self) -> Self {
        assert_ne!(self, Self(0, 0));
        self
    }
}
use std::{cmp::Ordering, ops::*};
impl PartialOrd for Rational {
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}
impl Ord for Rational {
    fn cmp(&self, other: &Self) -> Ordering {
        if self.1 == 0 && other.1 == 0 {
            self.0.cmp(&other.0)
        } else {
            (self.0 as i128 * other.1 as i128).cmp(&(self.1 as i128 * other.0 as i128))
        }
    }
}
impl Neg for Rational {
    type Output = Self;
    fn neg(self) -> Self {
        Self(-self.0, self.1)
    }
}
impl Add for Rational {
    type Output = Self;
    fn add(self, other: Self) -> Self {
        let g = gcd(self.1, other.1);
        let d = self.1 / g;
        Self(self.0 * (other.1 / g) + other.0 * d, d * other.1)
    }
}
impl Sub for Rational {
    type Output = Self;
    fn sub(self, other: Self) -> Self {
        self + -other
    }
}
impl Mul for Rational {
    type Output = Self;
    fn mul(self, other: Self) -> Self {
        let g1 = gcd(self.0, other.1);
        let g2 = gcd(self.1, other.0);
        Self(self.0 / g1 * other.0, self.1 / g2 * other.1).checked()
    }
}
impl Div for Rational {
    type Output = Self;
    fn div(self, other: Self) -> Self {
        self * other.inv()
    }
}
impl From<i64> for Rational {
    fn from(x: i64) -> Self {
        Self(x, 1)
    }
}
impl From<Rational> for f64 {
    fn from(r: Rational) -> f64 {
        r.0 as f64 / r.1 as f64
    }
}
fn gcd(x: i64, y: i64) -> i64 {
    if y == 0 {
        x
    } else {
        gcd(y, x % y)
    }
}

// -----------------------------------------------------------------------------
pub mod kyoproio {
    use std::io::prelude::*;
    pub trait Input {
        fn str(&mut self) -> &str;
        fn input<T: InputParse>(&mut self) -> T {
            T::input(self)
        }
        fn iter<T: InputParse>(&mut self) -> Iter<T, Self> {
            Iter(self, std::marker::PhantomData)
        }
        fn seq<T: InputParse, B: std::iter::FromIterator<T>>(&mut self, n: usize) -> B {
            self.iter().take(n).collect()
        }
    }
    pub struct KInput<R> {
        src: R,
        buf: String,
        pos: usize,
    }
    impl<R: BufRead> KInput<R> {
        pub fn new(src: R) -> Self {
            Self {
                src,
                buf: String::with_capacity(1024),
                pos: 0,
            }
        }
        pub fn src(&mut self) -> &mut R {
            &mut self.src
        }
    }
    impl<R: BufRead> Input for KInput<R> {
        fn str(&mut self) -> &str {
            loop {
                if self.pos >= self.buf.len() {
                    self.pos = 0;
                    self.buf.clear();
                    if self.src.read_line(&mut self.buf).expect("io error") == 0 {
                        return &self.buf;
                    }
                }
                let range = self.pos
                    ..self.buf[self.pos..]
                        .find(|c: char| c.is_ascii_whitespace())
                        .map(|i| i + self.pos)
                        .unwrap_or_else(|| self.buf.len());
                self.pos = range.end + 1;
                if range.end > range.start {
                    return &self.buf[range];
                }
            }
        }
    }
    pub struct Iter<'a, T, I: ?Sized>(&'a mut I, std::marker::PhantomData<*const T>);
    impl<'a, T: InputParse, I: Input + ?Sized> Iterator for Iter<'a, T, I> {
        type Item = T;
        fn next(&mut self) -> Option<T> {
            Some(self.0.input())
        }
    }
    pub trait InputParse: Sized {
        fn input<I: Input + ?Sized>(src: &mut I) -> Self;
    }
    impl InputParse for Vec<u8> {
        fn input<I: Input + ?Sized>(src: &mut I) -> Self {
            src.str().as_bytes().to_owned()
        }
    }
    macro_rules! from_str_impl {
        { $($T:ty)* } => {
            $(impl InputParse for $T {
                fn input<I: Input + ?Sized>(src: &mut I) -> Self {
                    src.str().parse::<$T>().expect("parse error")
                }
            })*
        }
    }
    from_str_impl! {
        String char bool f32 f64 isize i8 i16 i32 i64 i128 usize u8 u16 u32 u64 u128
    }
    macro_rules! tuple_impl {
        ($H:ident $($T:ident)*) => {
            impl<$H: InputParse, $($T: InputParse),*> InputParse for ($H, $($T),*) {
                fn input<I: Input + ?Sized>(src: &mut I) -> Self {
                    ($H::input(src), $($T::input(src)),*)
                }
            }
            tuple_impl!($($T)*);
        };
        () => {}
    }
    tuple_impl!(A B C D E F G);
    #[macro_export]
    macro_rules! kdbg {
        ($($v:expr),*) => {
            if cfg!(debug_assertions) {
                dbg!($($v),*)
            } else {
                ($($v),*)
            }
        }
    }
}