题目描述
We have a grid of squares with N rows and M columns. Let (i, j) denote the square at the i-th row from the top and j-th column from the left. We will choose K of the squares and put a piece on each of them.
If we place the K pieces on squares (x_1, y_1), (x_2, y_2), ..., and (x_K, y_K), 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 10^9+7.
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
- $2 \leq N \times M \leq 2 \times 10^5$
- $2 \leq K \leq N \times M$
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
N M K
Output
Print the sum of the costs of all possible arrangements of the pieces, modulo 10^9+7.
Examples
Input
2 2 2
Output
8
Input
4 5 4
Output
87210
Input
100 100 5000
Output
817260251
输入格式
见题面
输出格式
见题面