```cpp
#include<bits/stdc++.h>
#define pc __builtin_popcount
using namespace std;
int n,m,c,a[105],b[105],f[105][105][105];//f[i][now][lst]
void dfs(int dep,int s)
{
if(dep>m)
{
b[++c]=s;
return;
}
dfs(dep+1,s<<1);
dfs(dep+3,(s|1)<<3);
}
int main()
{
cin>>n>>m;
for(int i=1;i<=n;i++)
{
int s=0;
for(int j=1;j<=m;j++)
{
char ch;
cin>>ch;
s=(s<<1)|(ch=='H');
}
a[i]=s;
}
dfs(1,0);
for(int i=1;i<=c;i++)
{
if(a[1]&b[i]) continue;
f[1][i][0]=pc(b[i]);
}//line 1
for(int i=1;i<=c;i++)
{
if(a[2]&b[i]) continue;
for(int j=1;j<=c;j++)
{
if(b[i]&b[j]||a[1]&b[j]) continue;
f[2][i][j]=f[1][j][0]+pc(b[i]);
}
}//line 2
for(int i=3;i<=n;i++)//now
{
for(int j=1;j<=c;j++)//lst
{
if(a[i]&b[j]) continue;
for(int k=1;k<=c;k++)//lst of lst
{
if(b[j]&b[k]||a[i-1]&b[k]) continue;
for(int l=1;l<=c;l++)
{
if(b[j]&b[l]||b[k]&b[l]||a[i-2]&b[l]) continue;
f[i][j][k]=max(f[i][j][k],f[i-1][k][l]+pc(b[j]));
}
}
}
}//line 3~n
int ans=0;
for(int i=0;i<=c;i++)
{
for(int j=0;j<=c;j++)
{
ans=max(ans,f[n][i][j]);
}
}
cout<<ans;
return 0;
}
```
by Shiota_Kaede @ 2023-07-10 18:41:31
啊，标题写错了，是 10pts
by Shiota_Kaede @ 2023-07-10 18:42:07