Problem:
Twin Prime

Prime numbers are widely applied for cryptographic and communication technology.
A twin prime is a prime number that differs from another prime number by 2.
For example, (5, 7) and (11, 13) are twin prime pairs.

In this problem, we call the greater number of a twin prime "size of the twin prime."

Your task is to create a program which reads an integer n and prints a twin prime which has the maximum size among twin primes less than or equals to n

You may assume that 5 ≤ n ≤ 10000.

Input

The input is a sequence of datasets. The end of the input is indicated by a line containing one zero. Each dataset is formatted as follows:

n (integer)

Output

For each dataset, print the twin prime p and q (p < q). p and q should be separated by a single space.

Sample Input

12
100
200
300
0

Output for the Sample Input

5 7
71 73
197 199
281 283

Solution in JAVA (judge verdict: Wrong Answer)

import java.util.Arrays;
import java.util.Scanner;

public class Main {
	static boolean p[];
	public static void main(String[] args) {
		// TODO ツ篠ゥツ督ョツ青カツ青ャツつウツづェツつスツδソツッツドツ・ツスツタツブ
		Scanner sc=new Scanner(System.in);
		int n,i;

		while(true){
			n=sc.nextInt();
			if(n==0) break;
			p=new boolean[n];
			Arrays.fill(p, true);
			for(i=0;i<n;i++){
				p[i]=prime(i);
			}
			for(i=n-1;1<i-2;i--){
				if(p[i] && p[i-2]){
					System.out.println((i-2)+" "+i);
					break;
				}
			}
		}
	}
	static boolean prime(int n){
		int i;
		if(n<=1 || n%2==0) return false;

		for(i=3;i*i<=n;i+=2){
			if(n%i==0){
				return false;
			}
		}
		return true;
	}
}