#dpm. [dp_m]Candies
[dp_m]Candies
Problem Statement
There are children, numbered .
They have decided to share candies among themselves. Here, for each (), Child must receive between and candies (inclusive). Also, no candies should be left over.
Find the number of ways for them to share candies, modulo . Here, two ways are said to be different when there exists a child who receives a different number of candies.
Constraints
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
Output
Print the number of ways for the children to share candies, modulo .
Sample Input 1
3 4
1 2 3
Sample Output 1
5
There are five ways for the children to share candies, as follows:
Here, in each sequence, the -th element represents the number of candies that Child receives.
Sample Input 2
1 10
9
Sample Output 2
0
There may be no ways for the children to share candies.
Sample Input 3
2 0
0 0
Sample Output 3
1
There is one way for the children to share candies, as follows:
Sample Input 4
4 100000
100000 100000 100000 100000
Sample Output 4
665683269
Be sure to print the answer modulo .