class Solution:

"""

def the_maze_i_v(self, maps):

#

ret = 0

md = 0

dirs = [[-1, 0], [1, 0], [0, -1], [0, 1]]

paths = [set(), set()]

curr = 0

rows, cols = len(maps), len(maps[0])

for i in range(rows):

for j in range(cols):

if maps[i][j] == 'S':

paths[curr].add((i, j))

while paths[curr]:

if ret == 32:

k = 0

for i in range(rows):

for j in range(cols):

if maps[i][j] == '.':

k += 1

for p in paths[curr]:

if maps[p[0]][p[1]] == 'T':

return ret

for d in dirs:

r = p[0] + d[0]

c = p[1] + d[1]

if (r >= 0) and (r < rows) and (c >= 0) and (c < cols) and ((maps[r][c] == '.') or (maps[r][c] == 'T')):

paths[1 - curr].add((r, c))

maps[p[0]][p[1]] = '#'

paths[curr].clear()

curr = 1 - curr

ret += 1

return -1