module kkk
  sub main()
    
    dim n as integer
    dim s as string
    dim t as string
    
    dim i as integer
    dim a as string
    
    n = console.readline()
    s = console.readline()
    t = right(s, n)
    s = left(s, n)
    
    for i = 0 to n - 1
    a = a & right(left(s, i+1), 1) & right(left(t, i+1), 1)
    next
  
  console.writeline(a)
  
end sub
end module
  