> Hi, I tried to do this problem, but I always got Runtime Error. I don't know why, because I think my code is correct... Please help me...
> 
> Here is my code:
> 
> import java.io.*;
> import java.util.*;
> 
> class Main {
> 	
> 	static long x[];
> 	static long y[];
> 	public static int count(long mx, long my, int index) {
> 		
> 		int cont = 0;
> 		for (int i = 0; i < x.length; i ++)
> 			if (my * (x[index] - x[i]) == mx * (y[index] - y[i]))
> 				cont ++;
> 		
> 		return cont;
> 	}
> 	
> 	public static void main(String args[]) throws IOException {
> 		
> 		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
> 		StringTokenizer token;
> 		
> 		int casos = Integer.parseInt(in.readLine());
> 		x = new long[casos];
> 		y = new long[casos];
> 		
> 		for (int i = 0; i < casos; i ++) {
> 			
> 			token = new StringTokenizer(in.readLine());
> 			x[i] = Long.parseLong(token.nextToken());
> 			y[i] = Long.parseLong(token.nextToken());
> 		}
> 		
> 		int max = 1;
> 		for (int i = 0; i < casos - 1; i ++) {
> 			
> 			for (int j = i + 1; j < casos; j ++) {
> 				
> 				long mx = x[i] - x[j];
> 				long my = y[i] - y[j];
> 				
> 				int tmp = count(mx, my, i);
> 				if (tmp > max)
> 					max = tmp;
> 			}
> 		}
> 		System.out.println(max);
> 	}
> }