inp = open("DATA4.txt", "r+")                                                 
out = open("OUT4.txt", "w+")

data = []
mazes = [[]]

for line in inp:
    data.append(list(line.rstrip(" \r\n")))

i = 0
for part in data:
    if part[0] != "-":
        mazes[i].append(part)
    else:
        mazes.append([])
        i += 1

def place (bmap, cha):
    global time
    global tl
    if cha == False:
        return
    treeC = []
    fireC = []
    tl = False
    for y in range (len(bmap)):
        for x in range (len(bmap[0])):
            if bmap[y][x] == "T":
                tl = True
                treeC.append ([y,x])
            elif bmap[y][x] == "F":
                fireC.append ([y,x])
    time += 1
    burn (treeC, fireC, bmap)
    

def burn (t, f, bmap):
    
    change = False
    for fire in f:
        for tree in t:
            if (fire[0] + 1 == tree[0]) and ((fire[1] == tree[1])):
                bmap[fire[0]+1][fire[1]] = "F"
                change = True
            elif (fire[0] - 1 == tree[0]) and ((fire[1] == tree[1])):
                bmap[fire[0]-1][fire[1]] = "F"
                change = True
            elif (fire[0] == tree[0]) and ((fire[1] +1 == tree[1])):
                bmap[fire[0]][fire[1]+1] = "F"
                change = True
            elif (fire[0] == tree[0]) and ((fire[1] -1 == tree[1])):
                bmap[fire[0]][fire[1]-1] = "F"
                change = True
    place(bmap, change)

del mazes[-1]
for maz in mazes:
    time = -1
    tl = False
    place(maz,True)
    if tl == True:
        out.write("-1\n")
    else:
        out.write(str(time)+"\n")

out.close()