Problem Description

Simulate a cleaning robot in a grid. Robot starts at (0,0), cleans cells marked "C", avoids obstacles "#", and consumes 1 energy per move. Return total cells cleaned when energy runs out.

Input Format

First line: m n energy. Next m lines: grid with ".", "C", "#" characters.

Output Format

Number of cells cleaned before energy runs out.

Constraints

• 1 ≤ m, n ≤ 50

• 1 ≤ energy ≤ 1000

• Robot starts at (0,0)

• '.' = empty, 'C' = clean, '#' = obstacle

• Robot moves optimally to clean maximum cells

Sample Input/Output

Explanation

Robot starts at (0,0) with 5 energy. Optimal path to clean maximum cells within energy limit.