question-bit-strings.md

Time limit: 1.00 s    Memory limit: 512 MB

Your task is to calculate the number of bit strings of length $n$.

For example, if $n$ = 3, the correct answer is 8, because the possible bit strings are 000, 001, 010, 011, 100, 101, 110, and 111.

Input

The only input line has an integer $n$.

Output

Print the result modulo $10^{9}$ + $7$.

Constraints

• 1 $\le$ $n$ $\le$ $10^{6}$

Example

Input:
3

Output:
8