1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<cmath>
 5 #include<cstring>
 6 using namespace std;
 7 const int MAXN=105;
 8 
 9 int Map[MAXN], Plan[MAXN], Num[MAXN], dp[MAXN][MAXN][MAXN];
10 int N, m, cnt=0, ans;
11 
12 inline int get_one(int
 
 i){
13     int sum=0;
14     for (int x=i; x; x-=x & (-x)) sum++;
15     return sum;
16 }
17 
18 int main(){
19     scanf("%d%d", &N, &m);
20     for (int i=1; i<=N; i++){
21         char st[15];
22         scanf("%s", st+1);
23         int len=strlen(st+1);
24         for (int j=1; j<=len; j++) 
 
25             if (st[j]=='H') Map[i]+=(1<<j-1);
26     }      //記錄當前行的地形
27     for (int i=0; i<(1<<m); i++){
28         if ((!((i<<1)&i)) && (!((i>>1)&i)) && (!((i<<2)&i)) && (!((i>>2)&i))){
29             cnt++;
30             Plan[cnt]=i;
 
31             Num[cnt]=get_one(i);      //預處理當前行有幾個炮兵
32             if (!(Map[1] & Plan[cnt])) dp[1][cnt][0]=Num[cnt];      //預處理第一行的狀態
33         }
34     }
35     for (int i=1; i<=cnt; i++)
36         for (int j=1; j<=cnt; j++)
37             if ((!(Plan[i] & Plan[j])) && (!(Plan[j] & Map[2]))) 
38                 dp[2][j][i]=max(dp[1][i][0]+Num[j], dp[2][j][i]);
39 //預處理第二行的狀態
40     for (int i=3; i<=N; i++){
41         for (int j=1; j<=cnt; j++)
42             if (!(Plan[j] & Map[i])){
43                 for (int k=1; k<=cnt; k++)
44                     if (!(Plan[j] & Plan[k])){
45                         for (int q=1; q<=cnt; q++)
46                             if (!(Plan[j] & Plan[q]) && !(Plan[q] & Plan[k]))
47                                 dp[i][j][k]=max(dp[i][j][k], dp[i-1][k][q]+Num[j]);
48                     }
49             }
50     }
51 //Dp轉移
52     for (int i=1; i<=cnt; i++)
53         for (int j=1; j<=cnt; j++)
54             ans=max(ans, dp[N][i][j]);
55 //求最後一行的最值
56     printf("%d\n", ans);
57     return 0;
58 }