program main
	implicit none
	integer(8):: N,i,j,t,k
	character(200):: a, b, c
	read *, N
	read *, a,b
	do i=1,N*2
	if(mod(i,2)==1)then
	j=i/2+1
	 c(i:i)=a(j:j)
	 else 
	 j=i/2
	 c(i:i)=b(j:j)
	 end if
    end do
	print'(a)',c(1:N*2)
end program main