#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <string>
#include <iomanip>
#include <cmath>
#include <queue>
#include <map>
#include <stack>
#include <vector>
using namespace std;
#define long long LL
const int N = 1e3+5;
char a[N],b[N];
int lena,lenb,dp[N][N];
int main(){
	scanf("%s%s" , a + 1, b + 1);
	lena = strlen(a + 1);
	lenb = strlen(b + 1);
	for (int i = 1;i<=lena;i++)
	{
		for (int j = 1;j<=lenb;j++){
			if (a[i] == b[j]){
				dp[i][j] = dp[i - 1][j - 1] + 1; 
			}
			else{
				dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
			}
		}
	}
	cout << dp[lena][lenb];
	return 0;
}