#include <bits/stdc++.h>
using namespace std;
char s1[110], s2[110];
int f[510][510];
int a[5][5] = {
{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}
};
int ys[150];
int main()
{
    int n1, n2, K;
    scanf("%d%s", &n1, s1 + 1);
    scanf("%d%s", &n2, s2 + 1);
    ys['A'] = 0; ys['C'] = 1; ys['G'] = 2; ys['T'] = 3; ys['-'] = 4;
    f[0][0] = 0;
    for(int i = 1; i <= n1; i++) f[i][0] = f[i-1][0] + a[ys[s1[i]]][4];
    for(int j = 1; j <= n2; j++) f[0][j] = f[0][j-1] + a[4][ys[s2[j]]];
     
    for(int i = 1; i <= n1; i++)
        for(int j = 1; j <= n2; j++)
        {
            f[i][j] = max(f[i][j-1] + a[4][ys[s2[j]]], f[i-1][j] + a[ys[s1[i]]][4]);
            f[i][j] = max(f[i][j], f[i-1][j-1] + a[ys[s1[i]]][ys[s2[j]]]);
        }
     
    printf("%d\n", f[n1][n2]); 
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
char s1[110],s2[110];
int f[510][510];
int a[5][5]=
{
{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}
}
;
int ys[150];
int main()
{
    int n1,n2,K;
    scanf("%d%s",&n1,s1+1);
    scanf("%d%s",&n2,s2+1);
    ys['A']=0;ys['C']=1;ys['G']=2;ys['T']=3;ys['-']=4;
    f[0][0]=0;
    for(int i=1;i<=n1;i++)f[i][0]=f[i-1][0]+a[ys[s1[i]]][4];
    for(int j=1;j<=n2;j++)f[0][j]=f[0][j-1]+a[4][ys[s2[j]]];
     
    for(int i=1; i<=n1;i++)
        for(int j=1;j<=n2;j++)
        {
            f[i][j]=max(f[i][j-1]+a[4][ys[s2[j]]],f[i-1][j]+a[ys[s1[i]]][4]);
            f[i][j]=max(f[i][j],f[i-1][j-1]+a[ys[s1[i]]][ys[s2[j]]]);
        }
     
    printf("%d\n",f[n1][n2]); 
    return 0;
}