#!/c/Python34/python
# coding: utf-8
inf = 10**9


def dfs(y, x, val, H, W, C, D):
    for dx, dy in zip([0, 1, 0, -1], [-1, 0, 1, 0]):
        nx, ny = x+dx, y+dy
        if 0 <= nx < W and 0 <= ny < H:
            if C[ny][nx] == '.':
                if D[ny][nx] <= val:
                    continue
                D[ny][nx] = val
            else:
                if D[ny][nx] <= val+1:
                    continue
                D[ny][nx] = val + 1
            dfs(ny, nx, D[ny][nx], H, W, C, D)


def startPoint(H, W, C):
    for y in range(H):
        for x in range(W):
            if C[y][x] == '.':
                return x, y


def main():
    [W, H] = map(int, input().split())
    C = [input() for _ in range(H)]
    D = [[inf] * W for _ in range(H)]

    sx, sy = startPoint(H, W, C)
    D[sy][sx] = 0
    dfs(sy, sx, 0, H, W, C, D)
    ans = inf
    for y in range(H):
        for x in range(W):
            if C[y][x] == '.' and D[y][x] > 0:
                ans = min(ans, D[y][x])
    print(ans)
    return

if __name__ == '__main__':
    main()