//#pragma GCC target("avx2")
//#pragma GCC optimize("O3")
   
//#include <x86intrin.h>
#include <bits/stdc++.h>   
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace __gnu_pbds;
using namespace std;

template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
     
#define F first
#define S second           
#define lb lower_bound               
#define ub upper_bound
#define pb push_back
#define pf push_front    
#define ppb pop_back
#define mp make_pair
#define bpp __builtin_popcountll                                                                                        
#define sqr(x) ((x) * (x)) 
#define al 0x3F3F3F3F
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define in insert
#define ppf pop_front
//#define endl '\n'
//#define int long long
 
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef pair <int, int> pii;
 
const int mod = (int)1e9 + 7;
const int N = (int)3e5 + 123;
const ll inf = (ll)1e18 + 1;

const double pi = acos (-1.0);
const double eps = 1e-7;                  
const int dx[] = {0, 0, 1, 0, -1};
const int dy[] = {0, 1, 0, -1, 0};

int n, ans[202];
int res[202];

inline bool ask (vector <int> a) {
   cout << "? ";
   for (auto it : a) cout << it << ' ';
   cout << endl;
   fflush (stdout);
   string s;
   cin >> s;
   fflush (stdout);
   return (s == "Red");
}

inline void boost () {                    
   ios_base :: sync_with_stdio (NULL);
   cin.tie (NULL), cout.tie (NULL);          
}                                                     

inline void Solve () {
   cin >> n;
   vector <int> cur;
   cur.clear ();
   memset (res, -1, sizeof res);
   if (n == 1) {
      cur.pb (1);
      if (ask (cur)) res[1] = 1, res[2] = 0;
      else res[1] = 0, res[2] = 1;
      cout << "! ";
      for (int i = 1; i <= 2; i ++) cout << (res[i] ? "R" : "B");
      exit (0);
   }
   int L = 2, R = n + 1, i = -1;
   vector <int> q1, q2;
   for (int i = 1; i <= n; i ++) q1.pb (i);
   bool t = ask (q1);
   q1.clear ();
   while (L <= R) {
      int mid = L + R >> 1;
      q1.clear ();
      q2.clear ();
      for (int j = mid; j < mid + n; j ++) q1.pb (j);
      bool r1 = ask (q1);
      if (r1 != t) {
         i = mid;
         R = mid - 1;
      }
      else {
         L = mid + 1;
      }
   }
   ans[i] = (t ^ 1);
   ans[i - 1] = t;     
   assert (i != -1);
   int l = i, r = i + n - 2;  
   if (ans[i]) res[i - 1] = 0, res[i + n - 1] = 1;
   else res[i - 1] = 1, res[i + n - 1] = 0;
   cur.clear ();
   for (int k = l; k <= r; k ++) cur.pb (k); 
   for (int j = 1; j < l - 1; j ++) {
      cur.pb (j);
      if (ask (cur)) res[j] = 1;
      else res[j] = 0;
      cur.ppb ();    
   }
   for (int j = r + 2; j <= 2 * n; j ++) {
      cur.pb (j);
      if (ask (cur)) res[j] = 1;
      else res[j] = 0;
      cur.ppb ();    
   }
   cur.clear ();
   int red = n / 2, blue = n / 2;
   for (int j = 1; j <= n + n; j ++) {
      if (res[j] != -1) {
         if (res[j] && red > 0) red --, cur.pb (j);
         if (!res[j] && blue > 0) blue --, cur.pb (j);  
      }
   }
   for (int j = l; j <= r; j ++) {
      cur.pb (j);
      if (ask (cur)) res[j] = 1;
      else res[j] = 0;
      cur.ppb ();        
   }
   cout << "! ";
   for (int j = 1; j <= n + n; j ++) cout << (res[j] ? "R" : "B");
   fflush (stdout);
}

main () {                                       
// freopen (".in", "r", stdin);    
// freopen (".out", "w", stdout);              
   boost ();
   int tt = 1;
   //cin >> tt;   
   while (tt --) {
      Solve ();
   }                                               
   return 0;      
}
                          

Measured memory_bytes: 724