Forest

import java.util.*;

public class Kk21 {


    public static void main(String[] args) {
        // TODO code application logic here
        IO io = new IO();
        HashSet<Suunta> set = new HashSet<>();
        int n = io.nextInt();
        int ux,uy;
        int p =0;
        ux = io.nextInt();
        uy = io.nextInt();
        for (int i=0; i<n;i++){
            int x,y;
            x = io.nextInt();
            y = io.nextInt();
            set.add(new Suunta(x-ux,y-uy));
            
        }
        io.println(set.size());
	io.close();
        
    }
    
    private static class Suunta {
        int y;
        int x;
        int suunta;
        

        public Suunta(int x, int y) {
            this.y = y;
            this.x = x;
            suunta = x!=0?(x<0?-1:1):(y<0?-1:1) ;
        }

      

        @Override
        public int hashCode() {
            
            int hash = (y!=0?x/y:0)*5+23*(x!=0?y/x:0);
            return hash;
        }

        @Override
        public boolean equals(Object obj) {
            if (obj == null) {
                return false;
            }
            if (getClass() != obj.getClass()) {
                return false;
            }
            final Suunta o = (Suunta) obj;
            if(o.suunta!=suunta){
                return false;
            }
            return ((long)o.y)*this.x==((long)o.x)*this.y;
        }
        

        
        

        
        

        
        
        
        

        
        
        
    }
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED