#include <stdio.h>

int isprime(int n){
	for(int i=2;i*i<=n;i++){
		if(n%i==0) return 0;
	}
	return 1;
}

int main(){
	int n,i,prime[10000];
	for(i=3;i<10000;i++){
		prime[i]=isprime(i);
	}
	while(1){
		scanf("%d",&n);
		if(n==0){
			break;
		}
		for(i=n;i>=3;i--){
			if(prime[i]==1&&prime[i-2]==1){
				printf("%d %d\n",i-2,i);
				break;
			}
		}
	}
	return 0;
}
### Prompt

Construct a CPP code solution to the problem outlined:

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.

Example

Input

12
100
200
300
0


Output

5 7
71 73
197 199
281 283

### Response

```cpp
#include <stdio.h>

int isprime(int n){
	for(int i=2;i*i<=n;i++){
		if(n%i==0) return 0;
	}
	return 1;
}

int main(){
	int n,i,prime[10000];
	for(i=3;i<10000;i++){
		prime[i]=isprime(i);
	}
	while(1){
		scanf("%d",&n);
		if(n==0){
			break;
		}
		for(i=n;i>=3;i--){
			if(prime[i]==1&&prime[i-2]==1){
				printf("%d %d\n",i-2,i);
				break;
			}
		}
	}
	return 0;
}
```