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


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

for x in range(H):
    for y in range(W):
        
        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)

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