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 C (judge verdict: Wrong Answer)

#include<stdio.h>	
int main(){
	int n, i, k, one=0;
	int sosu[10000];
	for(i=0;i<100;i++){
		if(i%2!=0 && i%3!=0 && i%5!=0 && i%7!=0){
			sosu[i]=i;
		}else{ 
			sosu[i]=0;
		}
	}
	while(1){
		scanf("%d",&n);
		if(n==0) break;
		for(i=n;i>0 && one==0;i--){
			if(sosu[i]!=0 && sosu[i-2]!= 0){
				printf("%d %d\n",sosu[i-2],sosu[i]);
				one=1;
			}
		}
		one=0;
	}	
	return 0;
}