#include "bits/stdc++.h"
#pragma GCC optimize "03"
using namespace std;

#define int long long int
#define double long double
#define pb push_back
#define pii pair<int,int>
#define fi first
#define se second
#define rep(i,a,b) for (int i = a; i < b; ++i)
#define IOS ios_base::sync_with_stdio(false); cin.tie(NULL);
#ifndef LOCAL
#define dbg(...) ;
#define endl '\n'
#endif

const int inf = 1e15;
const int MOD = 1e9 + 7;
const int N = 2e5 + 5;



signed main(){
    IOS;
    int a, b;
    cin >> a >> b;
    if (b >= a) {
        int s = 0;
        vector<int> v;
        for (int i = 1; i <= b; i++) {
            v.push_back(-i);
            s -= i;
        }
        for (int i = 1; i < a; i++) {
            v.push_back(i);
            s += i;
        }
        s = -s;
        for (auto i : v)
            cout << i << " ";
        cout << s << endl;
    } else {
        int s = 0;
        vector<int> v;
        for (int i = 1; i <= a; i++) {
            v.push_back(i);
            s += i;
        }
        for (int i = 1; i < b; i++) {
            v.push_back(-i);
            s -= i;
        }
        s = -s;
        for (auto i : v)
            cout << i << " ";
        cout << s << endl;
    }
    return 0;
}

#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

struct Lucas {
    vector<vector<long long>> table;
    long long p;
    Lucas(long long _p) : p(_p) { init(p); }

    void init(long long p) {
        table.assign(p, vector<long long> (p));
        table[0][0] = 1;
        for(int i = 1; i < p; i++) {
            table[i][0] = 1;
            for(int j = i; j > 0; j--) {
                table[i][j] = (table[i - 1][j - 1] + table[i - 1][j]) % p;
            }
        }
    }

    long long comb(long long n, long long k) {
        long long ret = 1;
        while(n > 0) {
            ret *= table[n % p][k % p];
            ret %= p;
            n /= p;
            k /= p;
        }
        return ret;
    }
};

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);

    Lucas lu(3);
    int n,B=0,W=1,R=2; string s; cin >> n >> s;
    vector<int> a(n);
    rep(i,n){
        if(s[i] == 'B') a[i] = B;
        if(s[i] == 'W') a[i] = W;
        if(s[i] == 'R') a[i] = R;
    }

    int ans = 0;
    rep(i,n) ans = (ans + lu.comb(n - 1, i) * a[i]) % 3;
    if(n % 2 == 0) ans = (- ans + 3) % 3;
    if(ans == B) cout << 'B';
    if(ans == W) cout << 'W';
    if(ans == R) cout << 'R';
    cout << endl;
}