Fractions

## 题目描述 给定一个$n$，确定一些分数，使得这些分数的分母是$n$的因数，且$<n$，并且这些分数都是真分数，这些分数的和+$\frac{1}{n}=1$。 ## 输入格式 只有一行，是一个正整数$n$ ## 输出格式 如果无解输出一行"NO"（没有引号） 如果有解，先输出"YES"（没有引号），然后输出一个$k$，表示有多少个分数。接下来$k$行，每行两个数，是一个经过化简的分数，第一个是分子，第二个是分母。注意您输出的$k$要$<=10^5$，因为数据保证一定在$10^5$长度内有解。如果您输出的$k$超过了$10^5$，就会被判错（具体是$OLE$还是$WA$不知道，反正都是错了）。

You are given a positive integer $ n $ . Find a sequence of fractions $ \frac{a_i}{b_i} $ , $ i = 1 \ldots k $ (where $ a_i $ and $ b_i $ are positive integers) for some $ k $ such that: $ $$$ \begin{cases} \text{$b_i$ divides $n$, $1 < b_i < n$ for $i = 1 \ldots k$} \\ \text{$1 \le a_i < b_i$ for $i = 1 \ldots k$} \\ \text{$\sum\limits_{i=1}^k \frac{a_i}{b_i} = 1 - \frac{1}{n}$} \end{cases} $ $$$

The input consists of a single integer $ n $ ( $ 2 \le n \le 10^9 $ ).

In the first line print "YES" if there exists such a sequence of fractions or "NO" otherwise. If there exists such a sequence, next lines should contain a description of the sequence in the following format. The second line should contain integer $ k $ ( $ 1 \le k \le 100\,000 $ ) — the number of elements in the sequence. It is guaranteed that if such a sequence exists, then there exists a sequence of length at most $ 100\,000 $ . Next $ k $ lines should contain fractions of the sequence with two integers $ a_i $ and $ b_i $ on each line.

2

NO

6

YES
2
1 2
1 3

In the second example there is a sequence $ \frac{1}{2}, \frac{1}{3} $ such that $ \frac{1}{2} + \frac{1}{3} = 1 - \frac{1}{6} $ .