"""

author : https://github.com/daeunkwak

date : 2024-07-21

title : BOJ) LCS

"""

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.util.*;

public class LCS {

static char[] str1;

static char[] str2;

static int[][] dp;

static int LCS(int[][] dp) {

// ACAYK P & CAPCA K 를 비교함

// A & CAPCAK

// A & C -> A & CA -> A & CAP ->

// AC & A -> AC & CA -> AC & CAP

// ABC & ABC

// ABB & ABC

// ABB & AB, AB & ABC

for (int i = 1; i <= str1.length; i++) {

for (int j = 1; j <= str2.length; j++) {

// P != K

if (str1[i-1] == str2[j-1]) {

dp[i][j] = dp[i-1][j-1] + 1;

} else { // ACAYKP & CAPCA or ACAYK & CAPCAK 어느걸 비교해야 LCS이 큰지 고름

//

dp[i][j] = Math.max(dp[i][j-1], dp[i-1][j]);

}

}

}

return dp[str1.length][str2.length];

}

public static void main(String[] args) throws IOException{

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

StringTokenizer st1 = new StringTokenizer(br.readLine());

StringTokenizer st2 = new StringTokenizer(br.readLine());

str1 = st1.nextToken().toCharArray();

str2 = st2.nextToken().toCharArray();

dp = new int[str1.length+1][str2.length+1];

System.out.println(LCS(dp));

}

}