program ABC_072_B_OddString
   implicit none
   integer(8) i
   character(1000000) s
   read(*, *) s
   do i = 2, len_trim(s)
       s(i:i)= s(2*i-1:2*i-1)
   end do
   write(*, *) trim(s)
end program ABC_072_B_OddString