#include<......>
#define int long long
#define fo(i,a,b) for(int i=a;i<=b;i++)
using namespace std;
string a,b;
int f[1001][1001];
main(){
	cin>>a>>b;
	a='!'+a;
	b='!'+b;
	fo(i,1,a.size()-1){
		fo(j,1,b.size()-1){
			if(a[i]==b[j]){
				f[i][j]=f[i-1][j-1]+1;
			}
			else{
				f[i][j]=max(f[i-1][j],f[i][j-1]);
			}
		}
	}
	cout<<f[a.size()-1][b.size()-1];
}