character(50)S,T,ans
read*,S
read*,T
do i=len_trim(S)-len_trim(T)+1,1,-1
  if(check(S,T,i))then
    S(i:i+len_trim(T)-1)=trim(T)
    do j=1,Len_trim(S)
      if(S(j:j)=="?")S(j:j)="a"
    end do
    print"(A)",trim(S)
    stop
  endif
end do
print"(A)","UNRESTORABLE"
contains
pure function check(S,T,ind)
  implicit none
  character(50),intent(in)::S,T
  integer,intent(in)::ind
  integer::i
  logical::check
  check=.true.
  do i=1,len_trim(T)
    if(S(ind+i-1:ind+i-1)/=T(i:i).and.S(ind+i-1:ind+i-1)/="?")check=.false.
  end do
  return
end function
end