def neighborhood(i, j):
    return [(i+1, j), (i-1, j), (i, j+1), (i, j-1), (i+1, j+1), (i-1, j-1), (i-1, j+1), (i+1, j-1)]

def maxRegion(grid):
    largest_region_size = 0
    visited = set()
    for i in range(len(grid)-1):
        for j in range(len(grid[0])):
            if (i, j) in visited or grid[i][j] == 0:
                continue
            region_size = 1
            visited.add((i, j))
            stack = neighborhood(i, j)
            while stack:
                curr = stack.pop()
                if curr in visited or curr[0] < 0 or curr[1] < 0:
                    continue
                try:
                    if grid[curr[0]][curr[1]] == 0:
                        continue
                except:
                    continue
                visited.add((curr[0], curr[1]))
                region_size += 1
                stack.extend(neighborhood(curr[0], curr[1]))
            largest_region_size = max(largest_region_size, region_size)
                
            
    return largest_region_size