#P1445. [Violet] 樱花

[Violet] 樱花

Description

Find the number of ordered positive integer solutions to the equation:

1x+1y=1n!\dfrac{1}{x} + \dfrac{1}{y} = \dfrac{1}{n!}

Output the answer modulo 109+710^9+7.

Input Format

The input consists of a single integer nn.

Output Format

Output a single integer: the number of ordered positive integer pairs (x,y)(x, y) modulo 109+710^9+7.

2

3
1439

102426508

Hint

Sample 1 Explanation

There are three pairs (x,y)(x, y) that satisfy the condition: (3,6)(3,6), (4,4)(4,4), and (6,3)(6,3).

Constraints

  • For 30%30\% of the testdata, it is guaranteed that n100n \le 100.
  • For 100%100\% of the testdata, it is guaranteed that 1n1061 \le n \le 10^6.

Translated by ChatGPT 5