import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.TreeSet;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] sa = br.readLine().split(" ");
		int n = Integer.parseInt(sa[0]);
		int k = Integer.parseInt(sa[1]);
		char[] s = new char[n];
		for (int i = 0; i < k; i++) {
			sa = br.readLine().split(" ");
			int a = Integer.parseInt(sa[0]) - 1;
			char c = sa[1].charAt(0);
			s[a] = c;
		}
		br.close();

		StringBuilder sb = new StringBuilder();
		label:
		for (int i = 0; i < n; i += 3) {
			TreeSet<Character> set = new TreeSet<>();
			set.add('R');
			set.add('G');
			set.add('B');
			for (int j = 0; j < 3; j++) {
				int idx = i + j;
				if (idx >= n) {
					break label;
				}
				if (s[idx] == '\u0000') {
					sb.append(set.pollFirst());
				} else {
					if (set.contains(s[idx])) {
						sb.append(s[idx]);
						set.remove(s[idx]);
					} else {
						sb.append(set.pollFirst());
					}
				}
			}
		}
		System.out.println(sb.toString());
	}
}