#abc127e. [abc127_e]Cell Distance
[abc127_e]Cell Distance
Problem Statement
We have a grid of squares with rows and columns. Let denote the square at the -th row from the top and -th column from the left. We will choose of the squares and put a piece on each of them.
If we place the pieces on squares , , ..., and , the cost of this arrangement is computed as:
$\\sum_{i=1}^{K-1} \\sum_{j=i+1}^K (|x_i - x_j| + |y_i - y_j|)$
Find the sum of the costs of all possible arrangements of the pieces. Since this value can be tremendous, print it modulo .
We consider two arrangements of the pieces different if and only if there is a square that contains a piece in one of the arrangements but not in the other.
Constraints
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
Output
Print the sum of the costs of all possible arrangements of the pieces, modulo .
Sample Input 1
2 2 2
Sample Output 1
8
There are six possible arrangements of the pieces, as follows:
- , with the cost
- , with the cost
- , with the cost
- , with the cost
- , with the cost
- , with the cost
The sum of these costs is .
Sample Input 2
4 5 4
Sample Output 2
87210
Sample Input 3
100 100 5000
Sample Output 3
817260251
Be sure to print the sum modulo .