import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int k = sc.nextInt();
        char[] rgb = "RGB".toCharArray();
        HashMap<Integer, Character> exists = new HashMap<>();
        for (int i = 0; i < k; i++) {
            exists.put(sc.nextInt() - 1, sc.next().charAt(0));
        }
        char[] ans = new char[n];
        int idx = 0;
        for (int i = 0; i < n; i++) {
            if (i % 3 == 0) {
                if (exists.containsKey(i))  {
                    if (exists.get(i) == rgb[(idx + 1) % 3]) {
                        idx++;
                    } else if (exists.get(i) == rgb[(idx + 2) % 3]) {
                        idx += 2;
                    }
                }
                ans[i] = rgb[idx % 3];
                idx++;
            } else if (i % 3 == 1) {
                if (exists.containsKey(i) && exists.get(i) == rgb[(idx + 1) % 3]) {
                    if (i + 1 < n) {
                        ans[i + 1] = rgb[idx % 3];
                    }
                    idx++;
                    ans[i] = rgb[idx % 3];
                    idx++;
                    i++;
                } else {
                    ans[i] = rgb[idx % 3];
                    idx++;
                }
            } else {
                ans[i] = rgb[idx % 3];
                idx++;
            }
        }
        System.out.println(ans);
    }
}

class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}