题目描述
Problem Description
There is a board consisting of $ N $ rows and $ M $ columns, and each cell contains an integer from $ 1 $ to $N \times M$ in row-major order. That is, if we denote the integer written in the cell at the $ i $-th row and $ j $-th column as $ A_{i,j} $, then $A_{i,j} = (i-1) \times M + j$.
Count the number of subrectangles in this board whose internal values sum up to exactly $ V $.
More formally, count the number of quadruples of integers $ (a,b,c,d) $ ($1 \leq a \leq b \leq N$, $1 \leq c \leq d \leq M$) such that $\sum_{a \leq i \leq b, c \leq j \leq d} A_{i,j} = V$.
Input Format
The input is given from the standard input in the following format:
$ N $ $ M $ $ V $
Output Format
Output the answer.
Sample Input and Output
Sample Input #1
2 2 3
Sample Output #1
2
Sample Input #2
2 2 5
Sample Output #2
0
Sample Input #3
13 8 1032
Sample Output #3
5
Notes/Hints
Constraints
- $1 \leq N, M \leq 5000$
- $1 \leq V \leq 10^{15}$
- All values in the input are integers.
Sample Explanation 1
The board is filled with integers as follows:
1 2
3 4
The subrectangles that satisfy the condition are $ (a,b,c,d)=(1,1,1,2),(2,2,1,1) $, totaling 2.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分