from __future__ import print_function

def findd(a,b,k):

#print('aaa',a,b,k)

if len(a)==0:

return

w=-1

for i in range(len(b)):

#print(a.index(b[i]))

if k[i]!=0 and a.find(b[i])!=-1:

w=a.find(b[i])

k[i]=0

break

if w!=-1:

print(a[w],end='')

if w!=0 and w!=-1:

findd(a[:w],b,k)

if w!=len(a)-1 and w!=-1:

findd(a[w:],b,k)

return k

a=raw_input()

b=raw_input()

k=[1]*len(b)

b=list(b)

b.reverse()

b=''.join(b)

findd(a,b,k)

print()