#H. 位串数量Bit Strings

    Type: Default 1000ms 256MiB

位串数量Bit Strings

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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 109+710^9+7

Constraints

  • 1n10181≤n≤10^{18}

Example

3
8

训练题单一

Not Claimed
Status
Done
Problem
9
Open Since
2024-10-11 0:00
Deadline
2024-10-26 23:59
Extension
24 hour(s)