#include <iostream>
#include <cmath>

using namespace std;

#define LEFT 1
#define UP 2
#define SIKMO 3

struct Prvek{
	int c;
	int smer;
};


int main () {
	char p1[1000][11];
	char p2[1000][11];
	char sl[11];
	Prvek pr[1001][1001];
	int c1, c2;
	cin >> sl;
	while(true) {
	while(strcmp(sl,".")) {
		strcpy(p1[++c1],sl);
		cin >> sl;
	}
	cin >> sl;
	while(strcmp(sl,".")) {
		strcpy(p2[++c2], sl);
		cin >> sl;
	}
	for (int i = 1; i <= c1; i++) {
		for (int j = 1; j <= c2; j++) {
			pr[i][j].c = max(pr[i-1][j].c,pr[i][j-1].c);
			if (strcmp(p1[i],p2[j])==0) {
				pr[i][j].c++;
				pr[i][j].smer = SIKMO;
			}
			if (pr[i-1][j].c <= pr[i][j-1].c) {
				pr[i][j].smer = LEFT;
			}
			else pr[i][j].smer = UP;
		}
	}
	while (c1>0 && c2>0) {	
	if (pr[c1][c2].smer == LEFT) cout << p2[c2--];
	else if (pr[c1][c2].smer == UP) cout << p1[c1--];
	else {
		cout << p2[c2--];
		c1--;
	}
	}
		cin >> sl;
		if(!strcmp(sl, ".")) return 0;
	}
	return 0;
}