include[HTML_REMOVED]

using namespace std;
const int N=1010;
int f[N][N];
char a[N],b[N];
int main()
{
int n,m;
cin>>n>>m>>a+1>>b+1;
for(int i=1;i<=n;i)
{
for(int j=1;j<=m;j)
{
f[i][j]=max(f[i-1][j],f[i][j-1]);
if(a[i]==b[j])
f[i][j]=max(f[i-1][j-1]+1,f[i][j]);
}

}
cout<<f[n][m];
return 0;

}