! 2019.12.22
!
      program answer
      implicit none
      integer :: N
      character(len=100) :: S,T
      character(len=200) :: ans
      integer :: i,cn
      intrinsic trim
!
      read(*,*) N
      read(*,*) S,T
!
      cn = 0
      do i=1,N
        cn = cn+1
        ans(cn:cn) = S(i:i)
        cn = cn+1
        ans(cn:cn) = T(i:i)
      end do
      write(*,*) ans(1:2*N)
      end program answer