class RandomNums
  def self.generate size
    dec_nums (0...size).map{|i| rand(0...(size-i))}
  end

  private

  def self.dec_nums nums
    array = (0...nums.size).to_a
    nums.map{|i| array.delete_at(i)}
  end
end

# input
N = gets.to_i
A = N.times.map{
      gets.to_i
    }

def check_nums nums
  nums.each.with_index{|num, i|
    return i if nums[i] == A[i]
  }
  return nil
end

def change_nums nums, index
  indexs = (0...nums.size).to_a
  indexs.delete(index)
  i = indexs.sample
  nums[index], nums[i] = nums[i], nums[index]
end

def check_A
  A.each{|i| return false if i >= N}
  A.uniq.size == 1
end

if check_A
  p -1
else
  nums = RandomNums.generate N
  while (ng = check_nums(nums)) != nil
    change_nums nums, ng
  end
  nums.each{|i| p i }
end