Problem Statement

We have a grid of $H$ horizontal rows and $W$ vertical columns, where some of the squares contain obstacles. Let $(i, j)$ denote the square at the $i$-th row from the top and $j$-th column from the left. You are given $H$ strings $S_1, S_2, S_3, \dots, S_H$. The $j$-th character of $S_i$ describes the square $(i, j)$; # means the square contains an obstacle, and . means it does not. We say a square is visible from another when it is on the same row or the same column, and there is no obstacle between them (including themselves). Print the number of squares visible from the square $(X, Y)$ (including $(X, Y)$ itself).

Constraints

• $1 \le H \le 100$
• $1 \le W \le 100$
• $1 \le X \le H$
• $1 \le Y \le W$
• $S_i$ is a string of length $W$ consisting of . and #.
• The square $(X, Y)$ does not contain an obstacle.

Input

Input is given from Standard Input in the following format:

H W X Y
S_1
S_2
S_3
\hspace{3pt} \vdots
S_H

Output

Print the answer.