Score : 1000 points

Problem Statement

How many infinite sequences a_1, a_2, ... consisting of {{1, ... ,n}} satisfy the following conditions?

  • The n-th and subsequent elements are all equal. That is, if n \leq i,j, a_i = a_j.
  • For every integer i, the a_i elements immediately following the i-th element are all equal. That is, if i < j < k\leq i+a_i, a_j = a_k.

Find the count modulo 10^9+7.

Constraints

  • 1 \leq n \leq 10^6

Input

Input is given from Standard Input in the following format:

n

Output

Print how many sequences satisfy the conditions, modulo 10^9+7.

Sample Input 1

2

Sample Output 1

4

The four sequences that satisfy the conditions are:

  • 1, 1, 1, ...
  • 1, 2, 2, ...
  • 2, 1, 1, ...
  • 2, 2, 2, ...

Sample Input 2

654321

Sample Output 2

968545283