Largest color region

A piece of pixel art to use as a profile picture is given as the grid picture. picture[r][c] is the color of the cell in row r, column c, written as one uppercase English letter. Cells of the same color that touch each other above, below, left, or right form one region. Cells that touch only diagonally do not count as touching.

Complete the function solution, which returns the number of cells in the largest region.

Function

solution(picture)

Constraints

• The length of picture is from 1 to 30.
• The strings in picture all have the same length, which is from 1 to 30.
• The strings in picture consist only of uppercase English letters.

Examples

Starter code

def solution(picture):
    answer = 0
    return answer