You are given a positive integer n.
Find a sequence of fractions ai / bi, i = 1…k (where ai and bi are positive integers) for some k such that:
- bi divides n, 1 < bi < n for i = 1…k
- 1 ≤ ai < bi for i = 1…k
-
输入描述:
The input consists of a single integer n (2 ≤ n ≤ 109).
输出描述:
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 ≤ k ≤ 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 ai and bi on each line.
示例2
说明
In the second example there is a sequence 1/2, 1/3 such that 1/2 + 1/3 = 1 − 1/6
备注:
Author: Dmitry Yakutov