lcs.cpp

#include <iostream>
#include <string>
#include <cstring>
#include <algorithm>
using namespace std;
int main(){
	string s,t;
	cin>>s>>t;
	int n = s.length(),m = t.length();
	int dp[n][m];
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if(!i) dp[i][j] = j?dp[i][j-1]:0 || s[i] == t[j];
			else if(!j) dp[i][j] = dp[i-1][j] || s[i] == t[j];
			else dp[i][j] = max(dp[i-1][j],dp[i][j-1]) + (s[i] == t[j]);
		}
	}
	cout << dp[n-1][m-1] << endl;
	return 0;
}