#agc017a. [agc017_a]Biscuits
[agc017_a]Biscuits
Problem Statement
There are bags of biscuits. The -th bag contains biscuits.
Takaki will select some of these bags and eat all of the biscuits inside. Here, it is also possible to select all or none of the bags.
He would like to select bags so that the total number of biscuits inside is congruent to modulo . How many such ways to select bags there are?
Constraints
- or
Input
Input is given from Standard Input in the following format:
...
Output
Print the number of ways to select bags so that the total number of biscuits inside is congruent to modulo .
Sample Input 1
2 0
1 3
Sample Output 1
2
There are two ways to select bags so that the total number of biscuits inside is congruent to modulo :
- Select neither bag. The total number of biscuits is .
- Select both bags. The total number of biscuits is .
Sample Input 2
1 1
50
Sample Output 2
0
Sample Input 3
3 0
1 1 1
Sample Output 3
4
Two bags are distinguished even if they contain the same number of biscuits.
Sample Input 4
45 1
17 55 85 55 74 20 90 67 40 70 39 89 91 50 16 24 14 43 24 66 25 9 89 71 41 16 53 13 61 15 85 72 62 67 42 26 36 66 4 87 59 91 4 25 26
Sample Output 4
17592186044416