#include <stdio.h>
#include <assert.h>
#include <string.h>

FILE *input;

char a [200], b[200], aa [200], bb[200];

int k , l;

int read_case ()
{
  fscanf (input, "%s %s", aa, bb);
  if (feof (input))
    return 0;
  k = strlen (aa);
  for (int i = 0; i <= k + 1; i++)
    a [i + 1] = aa [i];
  l = strlen (bb);
  for (i = 0; i <= k + 1; i++)
    b [i + 1] = bb [i];
  b [0] = 0;
  a [0] = 0;
  
  return 1;
}

int comb [200][200];

void set (int i, int j, int c)
{
  if (comb [i][j] > c)
    comb [i][j] = c;
}

void paint_case (int i, int j)
{
  char ans [300];
  ans [comb [i][j]]= 0;
  while (i || j) {
    //    printf ("%d %d %d ", i, j, comb [i][j]);

    if (a [i] == b [j])
      {
	//	printf ("%c\n", a[i]);
	ans [comb [i][j] - 1] = a [i];
	i--; j--;
      }
   else if (i != 0 && comb [i - 1][j] == comb [i][j] - 1) {
     ans [comb [i][j] - 1] = a [i];
     //      printf ("%c\n", a [i]);
     i--;
   } else {
     //       printf ("%c\n", b [j]);
     ans [comb [i][j] - 1] = b [j];
     j--;
   }
  }
  printf ("%s\n", ans);
}

void solve_case ()
{
  int i, j;
  for (i = 0; i < 105; i++)
    for (j = 0; j < 105; j++)
      comb [i][j] = 100000;
  comb [0][0] = 0;
  for (i = 0; i <= k; i++){
    for (j = 0; j <= l; j++) {
      //      if (a [i] == b [j])
      //	{
      //	set (i + 1, j + 1, comb [i][j] + 1);
	//	}
      if (a [i + 1] == b [j] && comb [i][j - 1] < comb [i][j])
	set (i + 1, j, comb [i][j]);
      else
	set (i + 1, j, comb [i][j] + 1);
      if (a [i] == b [j + 1] && comb [i - 1][j] < comb [i][j])
     	set (i, j + 1, comb [i][j]);
      else
	set (i, j+ 1, comb [i][j] + 1);
      
    }
  } 
  /*  for (i = 0; i <= k; i++){
    printf ("%c ", a [i]);
    for (j = 0; j <= l; j++) {
      printf ("%d ", comb [i][j]);
    }
    printf ("\n");
    } */

  paint_case (k, l);
}

int main ()
{
  input = fopen ("fruits.in", "r");
  assert (input != NULL);
  while (read_case ()) solve_case ();
  fclose (input);
  return 0;
}