#include <iostream>
#include <string>
#define mod 3
using namespace std;
int n;
string s;
int dp[400000] = { 0 };
int f[400000] = { 0 };
int g[400000] = { 0 };
void compute()
{
    dp[0] = 1;
    f[0] = 0;
    g[0] = 1;
    for (int i = 1; i < n; ++i) {
        f[i] += f[i - 1];
        int j = i;
        while (j % mod == 0) {
            f[i]++;
            j /= mod;
        }
        g[i] = (g[i - 1] * j) % mod;
    }
    for (int i = 1; i < n; ++i) {
        if (f[n - 1] > f[i] + f[n - 1 - i]) {
            dp[i] = 0;
        } else {
            dp[i] = g[n - 1] * g[n - 1 - i] * g[i];
            dp[i] %= mod;
        }
    }
}
int convert(char c)
{
    if (c == 'B')
        return 0;
    if (c == 'R')
        return 1;
    if (c == 'W')
        return 2;
}
char revert(int num)
{
    if (num == 0)
        return 'B';
    if (num == 1)
        return 'R';
    if (num == 2)
        return 'W';
}
int main()
{
    cin >> n >> s;
    compute();
    int res = 0;
    for (int i = 0; i < n; ++i) {
        res += dp[i] * (convert(s[i])) % mod;
    }
    if ((n - 1) % 2) {
        res = -res;
    }
    res = ((res % mod) + mod) % mod;
    cout << revert(res) << endl;
}

#include <bits/stdc++.h>
#define LL long long

using namespace std;

LL n, k;

int main() {
  cin.tie(0), cout.tie(0);
  ios::sync_with_stdio(false);
  cin >> n >> k;
  while (k--) {
    if (n % 200) {
      n = n * 1000 + 200;
    } else {
      n /= 200;
    }
  }
  cout << n;
  return 0;
}
