#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, k; cin >> n >> k;
	vector<int>v(n, 0);
	rep(i, k) {
		int a; cin >> a; a--;
		char c; cin >> c;
		if ('R' == c)v[a] = 0;
		else if ('G' == c)v[a] = 1;
		else v[a] = 2;
	}
	vector<int>ans(n);
	rep(i, n) {
		int x = v[i];
		if (0 == i % 3) {
			ans[i] = v[i];
		}
		else if (1 == i % 3) {
			if (v[i] != ans[i - 1]) ans[i] = v[i];
			else ans[i] = (ans[i - 1] + 1) % 3;
		}
		else {
			ans[i] = 3 - ans[i - 1] - ans[i - 2];
		}
	}
	rep(i, n) {
		if (0 == ans[i])cout << 'R';
		else if (1 == ans[i])cout << 'G';
		else cout << 'B';
	}
	return 0;
}