A drawing canvas is a grid of R rows and C columns; each cell holds a single color given as a digit 0-9. A paint-bucket fill starts at a chosen cell and spreads to every cell reachable through shared edges (up, down, left, right) while staying on cells whose color equals the starting cell's color.
Report how many cells the fill would cover, counting the starting cell itself.
Input format
Line 1: two integers R and C.
Next R lines: a string of exactly C digit characters, the colors of that row.
Last line: two integers r and c (0-indexed), the starting cell's row and column.
Output format
A single integer: the number of cells covered by the fill (always at least 1).
Constraints
- 1 <= R, C <= 1000
- 0 <= r < R and 0 <= c < C
- Every grid character is a digit
0-9.