an = 3
ax = 'RRBBRB'

class TS
  def initialize(n, c)
    @n = n
    @c = c
    @q = [n]
    @limit = 210
  end
  
  def gets
    if @limit < 0
      "time limit exceeded\n"
    elsif @q.size == 0
      "no output"
    else
      @q.shift.to_s + "\n"
    end
  end
  
  def puts(w)
    $stderr.puts "puts(#{w})"
    w = w.split
    cmd = w.shift
    if cmd == '?'
      r = 0
      b = 0
      w.map(&:to_i).each do |i|
        if @c[i-1] == 'R'
          r += 1
        elsif @c[i-1] == 'B'
          b += 1
        else
          $stderr.puts("c[#{i}] = #{@c[i-1]}")
          @q.push(-1)
          return
        end
      end
      if r > b
        $stderr.puts("Red > Blue")
        @q.push("Red")
      elsif r < b
        $stderr.puts("Red < Blue")
        @q.push("Blue")
      else
        $stderr.puts("Red <?> Blue")
        @q.push(-1)
      end
    elsif cmd == '!'
      $stderr.puts("a=#{@c}")
      @q.push(w[0] == @c)
    else
      $stderr.push("unknown cmd #{w}")
      @q.push(-1)
    end
  end
end

class TC
  def initialize(in = $stdin, out = $stdout)
    @in = in
    @out = out
  end
  attr_accessor :in, :out
  
  def gets
    in.gets
  end
  
  def puts(w)
    out.puts(w)
    out.flush
  end
end

# サンプル通りの応答の確認
#ts = TS.new(3, 'RRBBRB')
#$stderr.puts ts.gets
#ts.puts "? 1 2 3"
#$stderr.puts ts.gets
#ts.puts "? 2 4 6"
#$stderr.puts ts.gets
#ts.puts "! RRBBRB"
#$stderr.puts ts.gets

def lookup(ts)
  n = ts.gets.to_i
  c = (1..(n*2)).map do |i|
    ts.puts("? #{i}")
    ret = ts.gets
    if ret.to_i == -1
      return "failed"
    end
    ret[0]
  end.join('')
  ts.puts("! #{c}")
  ts.gets
end

#ts = TS.new(3, 'RRBBRB')
#$stderr.puts lookup(ts)
#
#$stderr.puts lookup(TS.new(1, 'RB'))
#$stderr.puts lookup(TS.new(1, 'BR'))
lookup(TC.new())