      PROGRAM stringsWith
      IMPLICIT NONE
      character(100) :: s,t
      character(200) :: ans
      integer :: n
      integer :: i,c1=1,c2=1
      
      read*,n
      read*,s,t
      
      do i = 1,2*n
        if( mod(i,2)==1 )then
          ans(i:i) = s(c1:c1)
          c1 = c1 + 1
        else
          ans(i:i) = t(c2:c2)
          c2 = c2 + 1
        end if
      end do
      
      print*,ans(1:2*n)
      
      
      
      
      END PROGRAM