#include<bits/stdc++.h>
using namespace std;
int dp[1010][1010];
int main(){
    freopen("lcs.in", "r", stdin);
    freopen("lcs.out", "w", stdout);
    string a , b;
    cin >> a >> b;
    int x = a.size() , y = b.size();
    for (int i = 1;i <= x;i++){
        for (int j = 1;j <= y;j++){
            if (a[i - 1] == b[j - 1]){
                dp[i][j] = dp[i - 1][j - 1] + 1;
            }else {
                dp[i][j] = max(dp[i - 1][j] , dp[i][j - 1]);
            }
        }
    }
    cout << dp[x][y] << endl;
    return 0;
}