# Twin Prime

Time Limit : 1 sec, Memory Limit : 131072 KB
Japanese version is here

# 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.

```12
100
200
300
0
```

## Output for the Sample Input

```5 7
71 73
197 199
281 283
```

Source: PC Koshien 2007, Preliminary Round , All-Japan High School Programming Contest, Aizu-Wakamatsu, Japan, 2007
http://www.pref.fukushima.jp/pc-concours/