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.Scanner;


public class Main {

	
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		
		boolean primes[] = new boolean[10001];
		
		primes[0] = false;
		primes[1] = false;
		for(int i = 2; i < 10001; i++){
			primes[i] = true;
		}
		
		for(int i = 2; i < 101; i++){
			if(primes[i]){
				for(int j = 2*i; j < 10001; j += i){
					primes[j] = false;
				}
			}
		}
		
		while(true){
			final int N = sc.nextInt();
			
			if(N == 0){
				break;
			}
			
			int twin = 5;
			for(int i = 5; i <= N; i++){
				if(primes[i] && i <= (N - 2) && primes[i+2]){
					twin = i;
				}
			}
			
			System.out.println(twin + " " + (twin + 2));
		}
		
	}
}