program strings_with

 implicit none
 integer::n,i
 character::s*100,t*100,ans*200
 
 read*,n
 read*,s,t
! print*,s,t

 do i=1,n 
  ans(2*i-1:2*i-1)=s(i:i)
  ans(2*i:2*i)=t(i:i)
 end do
 
 print*,ans(1:2*n)

end program strings_with
