program main
  implicit none
  integer::N,K,i,j,l
  type bar
     integer::x,y
  end type bar
  integer::indx(100),pos(100),ans(100),temp
  type(bar)::bars(6000)
  data l/0/

  read *,N,K
  read *,bars(1:K)
  read *,ans(1:N)
  indx = (/(i,i=1,N)/)

  do i=1,K
     temp = indx(bars(i)%y)
     indx(bars(i)%y) = indx(bars(i)%x)
     indx(bars(i)%x) = temp
  end do

  do i=1,N
     pos(indx(i)) = i
  end do

  do i=1,N
     if(indx(i).eq.ans(i)) cycle
     l = l + 1
     bars(l)%x = i
     bars(l)%y = pos(ans(i))
     pos(indx(i)) = pos(ans(i))
     indx(pos(ans(i))) = indx(i)
     indx(i) = ans(i)
  end do

  print '(i0)', l
  do i=1,l
     print '(i0," ",i0)',bars(i)%x,bars(i)%y
  end do

end program main