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Description

Please write a program to calculate the sum of adjacent numbers for a given point in a 2D array. Adjacent numbers refer to the $8$ elements surrounding the point. If the point is at a corner or edge, the number of adjacent elements will be reduced accordingly.
For example, in the $4 \times 5$ 2D array $a$ shown below: The value of element $a[2][3]$ is $7$, and its adjacent elements are $8, 9, 10, 5, 8, 6, 8, 0$ with a sum of $54$. Another example: The value of element $a[1][0]$ is $6$, and its adjacent elements are $1, 2, 7, 3, 4$ with a sum of $17$.

1 2 3 4 5
6 7 8 9 10
3 4 5 7 8
2 5 6 8 0

Input Format

First line contains $4$ integers: $h$, $l$, $c$, $r$ representing the height and width of the 2D array, and the row and column indices of the specified point respectively.
Next $h$ lines contain the $l \times h$ int type 2D array $a$. Where $2 \le h, l \le 10$; and $0 \le c, r \le 9$; note that indices start from $0$.

Output Format

The sum of adjacent elements of $a[c][r]$.

Sample

4 5 2 3
1 2 3 4 5
6 7 8 9 10
3 4 5 7 8
2 5 6 8 0

54