//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
//#pragma GCC optimize("unroll-loops")
 
#include <iostream>
#include <stdlib.h>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <assert.h>
#include <memory.h>
#include <time.h>
#include <bitset>
 
#define uint unsigned int
#define ll long long
#define ull unsigned long long
#define ld long double
#define rep(i, l, r) for (int i = (l); i < (r); i++)
#define repb(i, r, l) for (int i = (r); i > (l); i--)
#define sz(a) (int)a.size()
#define fi first
#define se second
#define mp(a, b) make_pair(a, b)
#define rank qwertyuio
#define next dfghjk
#define plus fsghsf
#define minus ytryr
 
using namespace std;
 
inline bool setmin(int &x, int y) { return (y < x) ? x = y, 1 : 0; }
inline bool setmax(int &x, int y) { return (y > x) ? x = y, 1 : 0; }
inline bool setmin(ll &x, ll y) { return (y < x) ? x = y, 1 : 0; }
inline bool setmax(ll &x, ll y) { return (y > x) ? x = y, 1 : 0; }
 
const int N = 100000;
const int inf = (int)1e9 + 1;
const ll big = (ll)1e18 + 1;
const int P = 239;
const int P1 = 31;
const int P2 = 57;
const int MOD = (int)1e9 + 7;
const int MOD1 = (int)1e9 + 9;
const int MOD2 = 998244353;
const ld eps = 1e-12;
const double pi = atan2(0, -1);
const int ABC = 26;

int ask(vector<int> pos) {
    cout << "? ";
    for (int i : pos) {
        cout << i + 1 << " ";
    }
    cout << endl;
    string res;
    cin >> res;
    if (res[0] == 'R') {
        return 1;
    } else if (res[0] == 'B') {
        return -1;
    } else {
        assert(false);
    }
}

void answer(vector<int> ans) {
    cout << "! ";
    for (int i : ans) {
        if (i == 1) {
            cout << "R";
        } else if (i == -1) {
            cout << "B";
        } else {
            assert(false);
        }
    }
    cout << endl;
    exit(0);
}

vector<int> get_range(int l, int r) {
    vector<int> res;
    rep(i, l, r) {
        res.push_back(i);
    }
    return res;
}

int main()
{
    //freopen("a.in", "r", stdin);
    //freopen("a.out", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.precision(20);
    //ll TL = 10.95 * CLOCKS_PER_SEC;
    //clock_t time = clock();
    int n;
    cin >> n;
    if (n == 1) {
        vector<int> ans(n * 2, 0);
        rep(i, 0, n * 2) {
            ans[i] = ask({i});
        }
        answer(ans);
    }
    vector<int> segm(n + 1, 0);
    segm[0] = ask(get_range(0, 0 + n));
    segm[n] = -segm[0];
    int l = 0, r = n;
    while (r - l > 1) {
        int mid = (l + r) / 2;
        if (segm[mid] == 0) {
            segm[mid] = ask(get_range(mid, mid + n));
        }
        if (segm[mid] != segm[l]) {
            r = mid;
        } else {
            l = mid;
        }
    }
    vector<int> ans(n * 2, 0);
    int L, R;
    if (segm[l] != segm[l + 1]) {
        if (segm[l] == 1 && segm[l + 1] == -1) {
            ans[l] = 1;
            ans[l + n] = -1;
        } else {
            ans[l] = -1;
            ans[l + n] = 1;
        }
        L = l; R = l + n;
    } else {
        assert(false);
    }
    vector<int> pos1, pos2;
    rep(i, 0, n * 2) {
        if (i < L || i > R) {
            pos1.push_back(i);
        } else if (i > L && i < R) {
            pos2.push_back(i);
        }
    }
    rep(i, 0, n * 2) {
        if (i == L || i == R) {
            continue;
        }
        if (i < L || i > R) {
            pos2.push_back(i);
            ans[i] = ask(pos2);
            pos2.pop_back();
        } else {
            pos1.push_back(i);
            ans[i] = ask(pos1);
            pos1.pop_back();
        }
    }
    answer(ans);
    return 0;
}

Measured memory_bytes: 724