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 C# (.NET Core 3.1.201) (judge verdict: Wrong Answer)

using System;
using System.Linq;
using System.Collections.Generic;

namespace AtCoder.Contests.ABC168
{
    /// <summary>
    /// 
    /// </summary>
    static class E
    {
        static void Main(string[] args)
        {
            var n = NextInt();

            var counts = new CountDic<Tuple<int, long, long>>();
            var zeros = 0;
            for (int i = 0; i < n; i++)
            {
                var a = NextLong();
                var b = NextLong();

                if (a == 0 && b == 0)
                {
                    zeros++;
                    continue;
                }

                if (a == 0 || b == 0)
                {
                    var aoverb = new Tuple<int, long, long>(0, a == 0 ? 0 : 1, b == 0 ? 0 : 1);
                    continue;
                }

                var asign = a >= 0 ? 1 : -1;
                var bsign = b >= 0 ? 1 : -1;

                a *= asign;
                b *= bsign;

                var gcd = GCD.Solve(a, b);

                a = a / gcd;
                b = b / gcd;
                var aoberb = new Tuple<int, long, long>(asign * bsign, a, b);

                counts.CountUp(aoberb);
            }


            mint result = 1;
            var hash = new HashSet<Tuple<int, long, long>>();
            foreach (var kv in counts)
            {
                var key = kv.Key;
                var v = kv.Value;

                var bovera = new Tuple<int, long, long>(-key.Item1, key.Item3, key.Item2);
                if (key.Item1 == 0 || key.Item2 == 0)
                {
                    bovera = new Tuple<int, long, long>(0, key.Item1 == 0 ? 1 : 0, key.Item2 == 0 ? 1 : 0);
                }

                if (hash.Contains(bovera))
                {
                    continue;
                }
                if (hash.Contains(key))
                {
                    continue;
                }

                var opponents = counts[bovera];
                result *= 1 + (mint.Pow(2, v) - 1) + (mint.Pow(2, opponents) - 1);

                hash.Add(key);
                hash.Add(bovera);
            }

            result += zeros;

            Console.WriteLine(result - 1);
        }

        struct mint : IEquatable<mint>
        {
            //static uint mod = 998244353;
            public static uint mod = 1000000007;
            uint _v;

            public mint(long v) : this((uint)(v % mod + mod)) { }
            private mint(uint v)
            {
                _v = v < mod ? v : (v - mod);
            }

            public static void SetMod(uint p)
            {
                mod = p;
            }

            public static mint operator +(mint lhs, mint rhs)
            {
                return new mint(lhs._v + rhs._v);
            }
            public static mint operator -(mint lhs, mint rhs)
            {
                return new mint(lhs._v + mod - rhs._v);
            }
            public static mint operator *(mint lhs, mint rhs)
            {
                return new mint((uint)((ulong)lhs._v * rhs._v % mod));
            }
            public static mint operator /(mint lhs, mint rhs)
            {
                return lhs * rhs.Inv();
            }
            public static mint operator ^(mint x, int n)
            {
                return Pow(x, n);
            }
            public static bool operator ==(mint l, mint r)
            {
                return l._v == r._v;
            }
            public static bool operator !=(mint l, mint r)
            {
                return !(l == r);
            }
            public static bool operator <(mint l, mint r)
            {
                return l._v < r._v;
            }
            public static bool operator >(mint l, mint r)
            {
                return l._v > r._v;
            }

            public static mint Pow(mint x, int n)
            {
                var r = new mint(1);
                while (n > 0)
                {
                    if ((n & 1) > 0) r *= x;
                    x *= x;
                    n >>= 1;
                }
                return r;
            }

            public mint Pow(int n)
            {
                return Pow(this, n);
            }
            public mint Inv()
            {
                return Pow((int)mod - 2);
            }

            public bool Equals(mint o)
            {
                return this == o;
            }

            public override bool Equals(object obj)
            {
                if (obj is mint) return this == (mint)obj;
                else return false;
            }
            public override int GetHashCode()
            {
                return _v.GetHashCode();
            }
            public override string ToString()
            {
                return _v.ToString();
            }

            public static implicit operator mint(int i)
            {
                return new mint(i);
            }
            public static implicit operator mint(long i)
            {
                return new mint(i);
            }


            private static mint[] _fact;
            public static void SetFact(int n)
            {
                _fact = new mint[n + 1];
                _fact[0] = 1;
                for (int i = 1; i < n + 1; i++)
                {
                    _fact[i] = _fact[i - 1] * i;
                }
            }
            public static mint Fact(int n)
            {
                if (_fact == null || _fact.Length <= n)
                {
                    SetFact(n * 2);
                }
                return _fact[n];
            }

            public static mint Combination(int n, int r)
            {
                return Fact(n) / (Fact(n - r) * Fact(r));
            }
        }
        #region Console
        static int _index = 0;
        static string[] _buffer;

        static string Next()
        {
            if (_buffer == null || _index >= _buffer.Length)
            {
                _buffer = Console.ReadLine().Split();
                _index = 0;
            }

            return _buffer[_index++];
        }
        static int NextInt()
        {
            return int.Parse(Next());
        }
        static long NextLong()
        {
            return long.Parse(Next());
        }
        static int ReadInt()
        {
            return int.Parse(Console.ReadLine());
        }
        static long ReadLong()
        {
            return long.Parse(Console.ReadLine());
        }
        static int[] ReadIntArray()
        {
            return Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        }
        static int[] ReadIntArray(int n)
        {
            var a = new int[n];
            for (int i = 0; i < n; i++)
            {
                a[i] = ReadInt();
            }
            return a;
        }
        static long[] ReadLongArray()
        {
            return Console.ReadLine().Split(' ').Select(long.Parse).ToArray();
        }
        static long[] ReadLongArray(int n)
        {
            var a = new long[n];
            for (int i = 0; i < n; i++)
            {
                a[i] = ReadLong();
            }
            return a;
        }
        static List<T> ReadObjects<T>(int n, Func<int[], T> creator)
        {
            var l = new List<T>(n);

            for (int i = 0; i < n; i++)
            {
                var a = ReadIntArray();
                l.Add(creator(a));
            }

            return l;
        }

        static int[,] ReadMatrix(int n, int m)
        {
            var r = new int[n, m];
            for (int i = 0; i < n; i++)
            {
                var a = ReadIntArray();
                for (int j = 0; j < m; j++)
                {
                    r[i, j] = a[j];
                }
            }
            return r;
        }
        #endregion
    }
    class CountDic<T> : IDictionary<T, int>
    {
        private Dictionary<T, int> _dic = new Dictionary<T, int>();
        public int this[T key]
        {
            get
            {
                return Get(key);
            }

            set
            {
                _dic[key] = value;
            }
        }

        public ICollection<T> Keys
        {
            get
            {
                return _dic.Keys;
            }
        }

        public ICollection<int> Values
        {
            get
            {
                return _dic.Values;
            }
        }

        public int Count
        {
            get
            {
                return _dic.Count;
            }
        }

        public bool IsReadOnly
        {
            get
            {
                return false;
            }
        }

        public void Add(T key, int value)
        {
            _dic.Add(key, value);
        }

        public void Add(KeyValuePair<T, int> item)
        {
            throw new NotImplementedException();
        }

        public void Clear()
        {
            _dic = new Dictionary<T, int>();
        }

        public bool Contains(KeyValuePair<T, int> item)
        {
            return _dic.Contains(item);
        }

        public bool ContainsKey(T key)
        {
            return _dic.ContainsKey(key);
        }

        public void CopyTo(KeyValuePair<T, int>[] array, int arrayIndex)
        {
            throw new NotImplementedException();
        }

        public IEnumerator<KeyValuePair<T, int>> GetEnumerator()
        {
            return _dic.GetEnumerator();
        }

        public bool Remove(T key)
        {
            return _dic.Remove(key);
        }

        public bool Remove(KeyValuePair<T, int> item)
        {
            return _dic.Remove(item.Key);
        }

        public bool TryGetValue(T key, out int value)
        {
            value = Get(key);
            return true;
        }

        System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
        {
            return _dic.GetEnumerator();
        }

        private int Get(T key)
        {
            int c;
            if (_dic.TryGetValue(key, out c))
            {
                return c;
            }
            else
            {
                return 0;
            }
        }
        public int CountUp(T key)
        {
            var c = Get(key) + 1;
            _dic[key] = c;
            return c;
        }
    }
    class GCD
    {
        public static int Solve(int x, int y)
        {
            var a = Math.Max(x, y);
            var b = x + y - a;

            while (b != 0)
            {
                var c = b;
                b = a % b;
                a = c;
            }

            return a;
        }
        public static long Solve(long x, long y)
        {
            var a = Math.Max(x, y);
            var b = x + y - a;

            while (b != 0)
            {
                var c = b;
                b = a % b;
                a = c;
            }

            return a;
        }
    }
}