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-----
2

-----Sample Output-----
4

The four sequences that satisfy the conditions are:
- 1, 1, 1, ...
- 1, 2, 2, ...
- 2, 1, 1, ...
- 2, 2, 2, ...

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