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

ans = 0
def dfs(x, y, j):
    if x < 0 or x >= H or y < 0 or y >= W or Map[x][y] == "#":
        return
    if Map[x][y] == "x" and j-1 == 0:
        return
    if Map[x][y] == "x":
        j -= 1
    else:
        j += 1
    if x == W-1 and y == H-1:
        global ans
        ans += 1
        return
    dfs(x+1, y, j)
    dfs(x, y+1, j)

j = 1
dfs(0,0,j)
print(ans)