#include <fstream.h>
#include <string.h>

ifstream in("fruits.in");

char a[1000], b[1000], c[1000], d[1000];
int an, bn,cn;
int tab[1000][1000];

#define MAX(a,b) ((a)>(b)?(a):(b))


int main() {
  while (in >>a >> b){
    an = strlen(a);
    bn = strlen(b);

    //   cout <<a<<" "<<b<<" ";
    int i, j;
    
    for (i=0; i<=an; i++)
      tab[i][bn] = 0;

    for (j=0; j<=bn; j++)
      tab[an][j] = 0;

    for (i=an-1; i>=0; i--)
      for (j=bn-1; j>=0; j--)
	if (a[i] != b[j])
	  tab[i][j] = MAX(tab[i][j+1], tab[i+1][j]);
	else
	  tab[i][j] = 1+tab[i+1][j+1];

    i=j=0;
    cn = 0;
    while (tab[i][j]) {
      if (a[i] == b[j]) {
	c[cn++] = a[i];
	i++;
	j++;
      }
      else if (tab[i+1][j] >=tab[i][j+1] ) i++;
      else j++;
    }
    c[cn] = '\0';
    //  cout << c;

    i=j=0;
    int k, dn;
    k=dn=0;

    for (; i<an || j < bn || k < cn; ) {
      for( ; a[i] == b[j] && a[i] == c[k] && i < an && j<bn && k <cn; ) {
	d[dn++] = a[i++];
	j++;
	k++;
      }
      for( ;a[i] != c[k] && i<an; )
	d[dn++] = a[i++];
      for( ;b[j] != c[k] && j<bn; ) 
	     d[dn++] = b[j++];
    }

    d[dn]='\0';

    cout <<d<<endl;


  }
  in.close();
  return 0;
}