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

from collections import deque
Q=deque()

Q.append([0,0])
R=[[1<<30]*W for i in range(H)]
R[0][0]=0

while Q:
    x,y=Q.pop()

    for z,w in [[x+1,y],[x,y+1]]:
        if 0<=z<H and 0<=w<W:
            if MAP[z][w]==".":
                R[z][w]=min(R[z][w],R[x][y])

            else:
                R[z][w]=min(R[z][w],R[x][y]+z+w)

            Q.append((z,w))


print(H+W-2+R[-1][-1])