lib C
  fun strtoll(s : UInt8*, p : UInt8**, b : Int32) : Int64
end

class String
  def to_i64
    C.strtoll(self, nil, 10)
  end
end

n = read_line.to_i
s = read_line
if s.includes?('H') || s.includes?('9')
  puts -1; exit
end
cnt = s.count('Q')
sq = Math.sqrt(cnt).to_i
if cnt == 0 || sq ** 2 != cnt || n % sq != 0
  puts -1; exit
end
len = n // sq
t = s.chars.each_slice(len).to_a
if t.uniq.size != 1
  puts -1; exit
end
puts t[0].join