Queue

There is a queue with N people. Every person has a different heigth. We can see P people, when we are looking from the beginning, and R people, when we are looking from the end.It's because they are having different height and they are covering each other. How many different permutations of our queue has such a interesting feature?

Input

Each test case begins with a line containing a single integer number Nthat indicates the number of people in a queue (1 <= N <= 13). Then follows line containing two integers. The first integer corresponds to the number of people, that we can see looking from the beginning. The second integer corresponds to the number of people, that we can see looking from the end.

Output

For every test case your program has to determine one integer. Print how many permutations of N people we can see exactly P people from the beginning, and R people, when we are looking from the end.

Sample Input
3
10 4 4
11 3 1
3 1 2

Output for the Sample Input
90720
1026576
1