#include <iostream>
#include <map>

using namespace std;

const int N = 110;

char a[N],b[N];
int f[N][N];

int g[5][5]={//题意打标
    {5,-1,-2 ,-1,-3},
    {-1,5,-3 ,-2,-4},
    {-2,-3,5 ,-2,-2},
    {-1,-2, -2,5,-1},
    {-3,-4, -2,-1,0}
};

map<char,int>m;

int main()
{
    m['A']=0,m['C']=1,m['G']=2,m['T']=3,m['-']=4;
    int n,q;
    cin>>n>>a+1;
    cin>>q>>b+1;
    for(int i=1;i<=n;i++) f[i][0]=f[i-1][0]+g[m[a[i]]][4];
    for(int i=1;i<=q;i++) f[0][i]=f[0][i-1]+g[4][m[b[i]]];
    f[0][0]=0;//初始化
    //DP
    for(int i=1;i<=n;i++)
        for(int j=1;j<=q;j++)
        {
            f[i][j]=max(f[i-1][j]+g[m[a[i]]][4],f[i][j-1]+g[4][m[b[j]]]);
            f[i][j]=max(f[i][j],f[i-1][j-1]+g[m[a[i]]][m[b[j]]]);
        }
    cout<<f[n][q];
    return 0;
}