import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        Point[] points = new Point[n];
        for (int i = 0; i < n; i++) {
            points[i] = new Point(sc.nextInt(), sc.nextInt());
        }
        int ans = 0;
        for (int i = 0; i < n; i++) {
            HashSet<Vect> vects = new HashSet<>();
            for (int j = 0; j < n; j++) {
                if (i == j) {
                    continue;
                }
                Vect x = points[i].getVect(points[j]);
                if (vects.contains(x)) {
                    ans++;
                    break;
                }
                vects.add(x);
            }
        }
        System.out.println(ans);
    }
    
    static class Point {
        long x;
        long y;

        public Point(long x, long y) {
            this.x = x;
            this.y = y;
        }
        
        public Vect getVect(Point p) {
            return new Vect(x - p.x, y - p.y);
        }
    }
    
    static class Vect {
        long x;
        long y;
        
        public Vect(long x, long y) {
            this.x = x;
            this.y = y;
            init();
        }
        
        private void init() {
            long gcd = getGCD(Math.abs(x), Math.abs(y));
            x /= gcd;
            y /= gcd;
        }
        
        private long getGCD(long x, long y) {
            if (y == 0) {
                return x;
            } else {
                return getGCD(y, x % y);
            }
        }
        
        public int hashCode() {
            return (int)(x + y);
        }
        
        public boolean equals(Object o) {
            Vect v = (Vect)o;
            return x == v.x && y == v.y;
        }
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}