program main
  character(100)::SA,SB
  character(10000)::PA,PB
  character::XA,XB
  integer::len_pa,len_pb
  read *, SA, PA, XA
  read *, SB, PB, XB

  len_pa = len_trim(PA)
  len_pb = len_trim(PB)

  if (len_pa.gt.len_pb) then
     print '(a)', trim(SA)
  else if (len_pa.lt.len_pb) then
     print '(a)', trim(SB)
  else
     if (LGT(PA,PB)) then
        print '(a)', trim(SA)
        return
     else if (LLT(PA,PB)) then
        print '(a)', trim(SB)
        return
     else
        print '(a)',"-1"
     end if
  end if

end program main