CSES - Bit Strings
  • 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