H, W = map(int, input().split())
S = [input() for _ in range(H)]

L = [(0,0)]
Seen = [[False] * W for _ in range(H)]
add_one_possible = False
add_zero_possible = False
dx = [1, 0]
dy = [0, 1]
while len(L):
    (x, y) = L.pop()
    if(x == H - 1 and y == W - 1):
        add_zero_possible = True
        break
    if(x >= H - 2 or y >= W - 2):
        add_one_possible = True
    for k in range(2):
        x2 = x + dx[k]
        y2 = y + dy[k]
        if(x2 < H and y2 < W and  S[x2][y2] != "#" and not Seen[x2][y2]):
            Seen[x2][y2] = True
            L.append((x2, y2))
if(add_zero_possible):
    print(H + W - 2)
elif(add_one_possible):
    print(H + W - 1)
else:
    print(H + W)