def cavityMap(grid):
    arrlen = len(grid)
    cellidupdate = list()
    for i in range(1, arrlen-1):
        currentrow = list(grid[i])
        for j in range(1, arrlen-1):
            #print(grid[i])
            currcell = currentrow[j]
            _n = int(grid[i-1][j])
            _e = int(grid[i][j+1])
            _s = int(grid[i+1][j])
            _w = int(grid[i][j-1])
            if int(currcell) > max(_n, _e, _s, _w):
                cellidupdate.append([i,j])
    #print(cellidupdate)
    for i in cellidupdate:
        newrow = list(grid[i[0]])
        newrow[i[1]] = "X"
 
        grid[i[0]] = "".join( newrow)
 
    result = grid
    return result