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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.io.*;
import java.math.BigInteger;
import java.util.*;

// written by luchy0120

public class Main {
    public static void main(String[] args) throws Exception {

        new Main().run();
    }


    long gcd(long a,long b){
        return b==0?a:gcd(b,a%b);
    }

    class Pair{
        long x;long y;
        Pair(long xx,long yy){
            long fk = gcd(Math.abs(xx),Math.abs(yy));
            x =xx/fk;y =yy/fk;

            if(x<=0&&y<=0){
                x= -x;y=-y;
            }else if(x<=0||y<=0){
                x = -Math.abs(x);
                y = Math.abs(y);
            }

        }
        public int hashCode(){
            return Long.hashCode(x)<<17+Long.hashCode(y);
        }
        public boolean equals(Object other){
            Pair p = (Pair) other;
            return p.x==x&&p.y==y;
        }

        public Pair get() {
            return new Pair(-y, x);
        }
    }


    void solve() {
        int n = ni();

        HashMap<Pair,Integer> mp = new HashMap<>();
        long r = 0;
        int z = 0;
        for(int i=0;i<n;++i){
            long x = ni();
            long y = ni();
            if(x==y&&x==0){
                z++;
            }else{

                Pair cur = new Pair(x,y);
                mp.put(cur,mp.getOrDefault(cur,0)+1);


            }
        }

        long mod = 1000000007;
        long f[] = new long[1000001];
        f[0] =1;
        for(int i=1;i<=1000000;++i){
            f[i] = f[i-1]*2L;
            f[i] %= mod;
        }



        Set<Pair> st = new HashSet<>();
        r = 1;
        for(Pair k:mp.keySet()){
            if(st.contains(k)) continue;
            Pair ck = k.get();
            st.add(ck);
            if(mp.containsKey(ck)){
                r *= f[mp.get(k)] + f[mp.get(ck)]-1;
                r %= mod;
            }else{
                r *= f[mp.get(k)];
                r %= mod;
            }
        }
        r += z-1;
        r %= mod;
        
        

        println(r);

    }

    double dis(long x,long y,long a,long b){
        long v = (x-a)*(x-a)+(y-b)*(y-b);
        return Math.sqrt(v);
    }







    InputStream is;
    PrintWriter out;

    void run() throws Exception {
        //is = new FileInputStream(new File("C:\\Users\\Luqi\\Downloads\\P3387_9.in"));
        is = System.in;
        out = new PrintWriter(System.out);

        solve();
        out.flush();
    }

    private byte[] inbuf = new byte[1024];
    public int lenbuf = 0, ptrbuf = 0;

    private int readByte() {
        if (lenbuf == -1) throw new InputMismatchException();
        if (ptrbuf >= lenbuf) {
            ptrbuf = 0;
            try {
                lenbuf = is.read(inbuf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (lenbuf <= 0) return -1;
        }
        return inbuf[ptrbuf++];
    }

    private boolean isSpaceChar(int c) {
        return !(c >= 33 && c <= 126);
    }

    private int skip() {
        int b;
        while ((b = readByte()) != -1 && isSpaceChar(b)) ;
        return b;
    }

    private double nd() {
        return Double.parseDouble(ns());
    }

    private char nc() {
        return (char) skip();
    }

    private char ncc() {
        int b = readByte();
        return (char) b;
    }

    private String ns() {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while (!(isSpaceChar(b))) { // when nextLine, (isSpaceChar(b) && b != ' ')
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private char[] ns(int n) {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while (p < n && !(isSpaceChar(b))) {
            buf[p++] = (char) b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private String nline() {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while (!isSpaceChar(b) || b == ' ') {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private char[][] nm(int n, int m) {
        char[][] a = new char[n][];
        for (int i = 0; i < n; i++) a[i] = ns(m);
        return a;
    }

    private int[] na(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++) a[i] = ni();
        return a;
    }

    private long[] nal(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++) a[i] = nl();
        return a;
    }

    private int ni() {
        int num = 0, b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')) {
        }
        ;
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        while (true) {
            if (b >= '0' && b <= '9') num = (num << 3) + (num << 1) + (b - '0');
            else return minus ? -num : num;
            b = readByte();
        }
    }

    private long nl() {
        long num = 0;
        int b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')) {
        }
        ;
        if (b == '-') {
            minus = true;
            b = readByte();
        }
        while (true) {
            if (b >= '0' && b <= '9') num = num * 10 + (b - '0');
            else return minus ? -num : num;
            b = readByte();
        }
    }

    void print(Object obj) {
        out.print(obj);
    }

    void println(Object obj) {
        out.println(obj);
    }

    void println() {
        out.println();
    }

    void printArray(int a[],int from){
        int l = a.length;
        for(int i=from;i<l;++i){
            print(a[i]);
            if(i!=l-1){
                print(" ");
            }
        }
        println();
    }

    void printArray(long a[],int from){
        int l = a.length;
        for(int i=from;i<l;++i){
            print(a[i]);
            if(i!=l-1){
                print(" ");
            }
        }
        println();
    }
}