#include<bits/stdc++.h>

using namespace std;

string s1,s2;

int dp[5000][5000];

int main()
{
	cin >> s1 >> s2;
	
	for(int i = 1;i <= s1.length();i++)
	{
		for(int l = 1;l <= s2.length();l++)
		{
			if(s1[i - 1] == s2[l - 1]) dp[i][l] = dp[i - 1][l - 1] + 1;
			else dp[i][l] = max(dp[i - 1][l],dp[i][l - 1]);
		}
	}
	
	cout << dp[s1.length()][s2.length()] << "\n";

	return 0;
}