#D7480. Black Soul Gem
Black Soul Gem
Black Soul Gem
F: Red-Black Soul Gem
problem
Homu-chan has the mysterious power to change the soul game to red or black, and to connect two different soul games with a magic thread. By using this power, Homu-chan can create a magic square by Sorujemu.
Homu-chan was wondering how many different magic squares there were when there were N numbered magic squares numbered from 1 to N, and the following conditions were met:
- You can only connect once between any of the two sources.
- All the colors of the game are either red or black.
- For any game, it is connected to at least one of the games whose color is different from its own.
At this time, the magic square can be regarded as a graph with the sorujemu as the apex and the magic thread as the side. Note that the graph does not have to be concatenated.
Homu-chan is not good at calculating, so let's create a fast program instead and calculate the number of different magic squares. However, the number is expected to be very large, so we will find the remainder after dividing by a prime number M.
Note that the magic squares G and H are different because the colors of G and H are different for a certain magic square v, or the pair u and v of a certain magic square is one of G and H. It means that it is connected only with.
Input format
N M
Constraint
- 2 \ leq N \ leq 2,000
- 10 ^ 8 \ leq M \ leq 10 ^ 9 + 7
- M is guaranteed to be prime
Output format
Divide the number of graphs that satisfy the condition by M and output the remainder as an integer on one line.
Input example 1
3 310779401
Output example 1
12
For example, the following magic squares meet the conditions.
Input example 2
7 566666561
Output example 2
98638848
For example, the following magic squares meet the conditions.
Input example 3
1010 1000000007
Output example 3
862232855
Note that we output the remainder after dividing by M.
Example
Input
3 310779401
Output
12
inputFormat
Input format
N M
Constraint
- 2 \ leq N \ leq 2,000
- 10 ^ 8 \ leq M \ leq 10 ^ 9 + 7
- M is guaranteed to be prime
outputFormat
Output format
Divide the number of graphs that satisfy the condition by M and output the remainder as an integer on one line.
Input example 1
3 310779401
Output example 1
12
For example, the following magic squares meet the conditions.
Input example 2
7 566666561
Output example 2
98638848
For example, the following magic squares meet the conditions.
Input example 3
1010 1000000007
Output example 3
862232855
Note that we output the remainder after dividing by M.
Example
Input
3 310779401
Output
12
样例
3 310779401
12