INF = 1<<60

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

dp = [[False]*W for _ in range(H)]
dpR = [[False]*W for _ in range(H)]
dp[0][0] = True
dpR[H-1][W-1] = True
maxH, maxW = -INF, -INF
minH, minW = INF, INF
for i in range(H):
    for j in range(W):
        if dp[i][j]:
            maxH = max(maxH, i)
            maxW = max(maxW, j)
            if i+1 < H and S[i+1][j] != "#":
                dp[i+1][j] = True
            if j+1 < W and S[i][j+1] != "#":
                dp[i][j+1] = True
for i in reversed(range(H)):
    for j in reversed(range(W)):
        if dpR[i][j]:
            minH = min(minH, i)
            minW = min(minW, j)
            if 1 <= i and S[i-1][j] != "#":
                dpR[i-1][j] = True
            if 1 <= j and S[i][j-1] != "#":
                dpR[i][j-1] = True

if dp[-1][-1]:
    print(H+W-2)
elif minH <= maxH+1 or minW <= maxW+1:
    print(H+W-1)
else:
    print(H+W)