T = gets.to_i

target = 'helloworld'

T.times do
  n = gets.to_i
  s = gets.chomp
  best_idx = -1
  list = []

  (n - 10).downto(0) do |i|
    ok = true
    idx = 0

    while ok && idx < 10
      if target[idx] == s[i + idx] || s[i + idx] == '?'
        # NOOP
      else
        ok = false
      end

      idx += 1
    end

    if ok
      t = s.dup
      10.times do |idx|
        if t[i + idx] == '?'
          t[i + idx] = target[idx]
        end
      end

      t.tr!('?', 'a')
      list << t
    end
  end

  if list.size > 0
    puts list.sort[0]
  else
    puts -1
  end
end