#include<bits/stdc++.h>
using namespace std;

int main(){
	string a,b;
	while(cin>>a>>b){
		int x=0,y=0;
		int l1=a.length();
		int l2=b.length();
		vector<vector<int> > dp(l1+1,vector<int>(l2+1,0));
		for(int i=1;i<=l1;i++){
			for(int j=1;j<=l2;j++){
				if(a[i]<='9' && a[i]>='0') {dp[i][j]=dp[i-1][j];continue;}
				else if(b[j]<='9' && b[j]>='0')  {dp[i][j]=dp[i][j-1];continue;}
				if(a[i-1]==b[j-1]) {
					dp[i][j]=dp[i-1][j-1]+1;
					if(dp[x][y]<dp[i][j]){
						x=i;y=j;
					}
				}
				else {
					dp[i][j]=0;
				}
			}
		}
		for(int i=0;i<dp[x][y];i++){
			cout<<a[x-dp[x][y]+i];
		}
		cout<<endl;
	}
		
}