PROGRAMMING:Prime pair
###Task description
```
Two prime numbers with a difference of 2 are called prime pairs, such as 5 and 7, 17 and 19, etc.
```
###Input format:
```
A positive integer n. 1 <= n <= 10000。
```
###Output format:
```
All prime pairs less than or equal to n. Each pair of prime output a line, separated by a single space. If no prime pair is found, output empty.
```
###Input example:
```in
one hundred
```
###Output example:
```out
3 5
5 7
11 13
17 19
29 31
41 43
59 61
71 73
```
###Title Source
Note: this topic is selected from openjudge website http://noi.openjudge.cn/ch0112/10/
answer：If there is no answer, please comment
```
Two prime numbers with a difference of 2 are called prime pairs, such as 5 and 7, 17 and 19, etc.
```
###Input format:
```
A positive integer n. 1 <= n <= 10000。
```
###Output format:
```
All prime pairs less than or equal to n. Each pair of prime output a line, separated by a single space. If no prime pair is found, output empty.
```
###Input example:
```in
one hundred
```
###Output example:
```out
3 5
5 7
11 13
17 19
29 31
41 43
59 61
71 73
```
###Title Source
Note: this topic is selected from openjudge website http://noi.openjudge.cn/ch0112/10/
answer：If there is no answer, please comment