#include <bits/stdc++.h>

int ri() {
	int n;
	scanf("%d", &n);
	return n;
}

int main() {
	int n = ri();
	int k = ri();
	int limit[n];
	for (auto &i : limit) i = 0;
	for (int i = 0; i < k; i++) {
		int a = ri() - 1;
		std::string t;
		std::cin >> t;
		limit[a] = t[0] == 'R' ? 0 : t[0] == 'G' ? 1 : 2;
	}
	std::string res;
	int cnt[3] = {1, 1, 1};
	for (int i = 0; i < n; i++) {
		if (cnt[limit[i]]) res.push_back("RGB"[limit[i]]), cnt[limit[i]]--;
		else {
			for (int j = 0; j < 3; j++) if (cnt[j]) {
				cnt[j]--;
				res.push_back("RGB"[j]);
			}
		}
		if (i % 3 == 2) {
			cnt[0] = cnt[1] = cnt[2] = 1;
		}
	}
	std::cout << res << std::endl;
	return 0;
}