zmey

q = deque([])
visited = [[[-1, -1, -1, -1] for _ in range(m)] for _ in range(len(grid))]

for i in range(len(grid)):
    for j in range(m):
        if grid[i][j] == 'S':
            q.append((i, j, 0))
            visited[i][j][0] = 0
            q.append((i, j, 1))
            visited[i][j][1] = 0
            q.append((i, j, 2))
            visited[i][j][2] = 0
            q.append((i, j, 3))
            visited[i][j][3] = 0
        if grid[i][j] == 'F':
            xe, ye = i, j


while q:
    x, y, direction = q.popleft()

    for xp, yp, dir_old, dir_new in [(x-1, y, 0, 0), (x, y+1, 0, 1), (x, y+1, 1, 1), (x+1, y, 1, 2),
        (x+1, y, 2, 2), (x, y-1, 2, 3), (x, y-1, 3, 3), (x-1, y, 3, 0)]:

        if dir_old == direction and grid[xp][yp] != 'X' and visited[xp][yp][dir_new] == -1:
            q.append((xp, yp, dir_new))
            visited[xp][yp][dir_new] = visited[x][y][dir_old] + 1


print(min([elem for elem in visited[xe][ye] if elem > 0]))