INF = 1e18
import sys
sys.set_int_max_str_digits(0)
H, W = map(int, input().split())
A = [input() for _ in range(H)]
dp = [[INF] * (W) for _ in range(H)]
dp[0][0] = 0

for i in range(H):
    for j in range(W):
        
        if i == j == 0:
            continue

        sub = INF
        # 上
        if i != 0:
            sub = min(sub, dp[i - 1][j] + 1)
        # 左
        if j != 0:
            sub = min(sub, dp[i][j - 1] + 1)

        if A[i][j] == '.':
            dp[i][j] = sub
        else:
            dp[i][j] = sub + (i + j)

ans = dp[-1][-1]
print(ans)