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

L = [(0,0)]
Seen = [[False] * W for _ in range(H)]
dx = [1, 0]
dy = [0, 1]
S_height = 0
S_width = 0
while len(L):
    (x, y) = L.pop()
    if(x == H - 1 and y == W - 1):
        print(H + W - 2)
        exit()
    S_height = max(x, S_height)
    S_width = max(y, S_width)
    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))
L = [(H - 1,W - 1)]
Seen = [[False] * W for _ in range(H)]
dx = [-1, 0]
dy = [0, -1]
G_height = H - 1
G_width = W - 1
while len(L):
    (x, y) = L.pop()
    G_height = min(x, G_height)
    G_width = min(y, G_width)
    for k in range(2):
        x2 = x + dx[k]
        y2 = y + dy[k]
        if(0 <= x2  and 0 <= y2 and  S[x2][y2] != "#" and not Seen[x2][y2]):
            Seen[x2][y2] = True
            L.append((x2, y2))

if(G_height - S_height <= 1 or G_width - G_height <= 1):
    print(H + W -1)
else:
    print(H + W)