import java.util.*;

public class _9251 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String s1 = sc.nextLine().trim();
        String s2 = sc.nextLine().trim();
        sc.close();

        int l1 = s1.length(), l2 = s2.length();
        int[][] lcs = new int[l1+1][l2+1];
        
        for(int i=1; i<=l1; i++) {
            for(int j=1; j<=l2; j++) {
                if(s1.charAt(i-1) == s2.charAt(j-1)) {
                    lcs[i][j] = lcs[i-1][j-1] + 1;
                }
                else {
                    lcs[i][j] = Math.max(lcs[i-1][j], lcs[i][j-1]);
                }
            }
        }
        System.out.println(lcs[l1][l2]);
    }
}