Problem:
Score : 300 points

Problem Statement

There are N balls in a two-dimensional plane. The i-th ball is at coordinates (x_i, y_i).

We will collect all of these balls, by choosing two integers p and q such that p \neq 0 or q \neq 0 and then repeating the following operation:

Choose a ball remaining in the plane and collect it. Let (a, b) be the coordinates of this ball. If we collected a ball at coordinates (a - p, b - q) in the previous operation, the cost of this operation is 0. Otherwise, including when this is the first time to do this operation, the cost of this operation is 1.

Find the minimum total cost required to collect all the balls when we optimally choose p and q.

Constraints

1 \leq N \leq 50

|x_i|, |y_i| \leq 10^9

If i \neq j, x_i \neq x_j or y_i \neq y_j.

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
x_1 y_1
:
x_N y_N

Output

Print the minimum total cost required to collect all the balls.

Sample Input 1

2
1 1
2 2

Sample Output 1

1

If we choose p = 1, q = 1, we can collect all the balls at a cost of 1 by collecting them in the order (1, 1), (2, 2).

Sample Input 2

3
1 4
4 6
7 8

Sample Output 2

1

If we choose p = -3, q = -2, we can collect all the balls at a cost of 1 by collecting them in the order (7, 8), (4, 6), (1, 4).

Sample Input 3

4
1 1
1 2
2 1
2 2

Sample Output 3

2

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

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

public class Main {

    static class Coord {
        int x;
        int y;

        public Coord(int x, int y) {
            this.x = x;
            this.y = y;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Coord coord = (Coord) o;
            return x == coord.x &&
                    y == coord.y;
        }

        @Override
        public int hashCode() {
            return Objects.hash(x, y);
        }
    }

    public static void main(String[] args) throws Exception {
        MyScanner scan = new MyScanner();
        out = new PrintWriter(new BufferedOutputStream(System.out));

        int n = scan.nextInt();
        int[][] coords = new int[n][2];
        HashSet<Coord> coordMap = new HashSet<>();
        for (int i = 0; i < n; i++) {
            coords[i][1] = scan.nextInt();
            coords[i][0] = scan.nextInt();
            coordMap.add(new Coord(coords[i][1], coords[i][0]));
        }
        HashMap<Coord, Integer> grads = new HashMap<>();
        Coord maxGrad = null;
        int maxCount = 0;
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                int deltaX = coords[i][1] - coords[j][1];
                int deltaY = coords[i][0] - coords[j][0];
                Coord coo = new Coord(deltaX, deltaY);
                grads.put(coo, grads.getOrDefault(coo, 0) + 1);
                if (maxCount < grads.get(coo)) {
                    maxCount = grads.get(coo);
                    maxGrad = coo;
                }
            }
        }
        if (maxGrad == null) {
            out.println(1);
        } else {
            for (int i = 0; i < n; i++) {
                int currX = coords[i][1];
                int currY = coords[i][0];
                Coord next = new Coord(currX + maxGrad.x, currY + maxGrad.y);
                while (coordMap.contains(next)) {
                    currX = currX + maxGrad.x;
                    currY = currY + maxGrad.y;
                    coordMap.remove(next);
                    next = new Coord(currX + maxGrad.x, currY + maxGrad.y);
                }
            }
            out.println(coordMap.size());
        }

        out.close();
    }

    //-----------PrintWriter for faster output---------------------------------
    public static PrintWriter out;

    //-----------MyScanner class for faster input----------
    public static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        public MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }

    }
    //--------------------------------------------------------

}