def question(query)
  puts query.join(" ")
  STDOUT.flush
  s = gets.chomp
  return s
end

N = gets.to_i
ans = [-1] * (N+1)

query = []
rest = []
N.times do |i|
  query << i+1
  rest << N+i+1
end

res1 = question(query)

while 
  a = rest.shift
  b = query.shift
  query << a
  rest << b
  res = question(query)
  if res != res1
    ans[a] = res == "Red" ? "R" : "B"
    ans[b] = res == "Red" ? "B" : "R"
    break
  end
end
query.delete(a)
rest.delete(b)

1.upto(2*N) do |i|
  next if query.include?(i) || ans[i] != -1
  r = question(query + [i])
  ans[i] = r == "Red" ? "R" : "B"
end

1.upto(2*N) do |i|
  next if rest.include?(i) || ans[i] != -1
  r = question(rest + [i])
  ans[i] = r == "Red" ? "R" : "B"
end

puts "! #{ans[1,2*N].join}"
exit