Alternating Maze Traversal

You are given an $n\times n$ maze consisting only of the digits $0$ and $1$. If you are in a cell with value $0$, you can move to any one of its $4$ adjacent cells (up, down, left, right) that contains a $1$. Similarly, if you are in a cell with value $1$, you can move to any one of its $4$ adjacent cells that contains a $0$.

Your task is to determine how many cells can be reached (including the starting cell) if you start from a specified cell.

inputFormat

The input begins with an integer $n$, denoting the size of the maze. The next line contains two integers $r$ and $c$ (0-indexed) which represent the starting cell. This is followed by $n$ lines, each containing $n$ space-separated integers (each either $0$ or $1$) representing the maze.

outputFormat

Output a single integer indicating the total number of cells reachable from the starting cell (including the starting cell itself) according to the alternating move rules.

sample

3
0 0
0 1 0
1 0 1
0 1 0

9