N=gets.to_i
A=[0]+gets.split.map(&:to_i)
puts (1..N).map{|i|
  t=[i]
  j=A[i]
  until j==i
    t<< j
    j=A[j]
  end
  t.sort
}.uniq.count{|a|a.size%2<1}%2<1?:Yes:"No"