typedef long long ll;
typedef long double ld;
#include <bits/stdc++.h>
using namespace std;
#define int long long

signed main(){
    ll n,k;
    std::cin >> n>>k;
    vector<vector<pair<ll,char>>> ama(2);
    for (int i = 0; i < k; i++) {
        ll a;
        char c;
        std::cin >> a>>c;
        if(a%3==1){
            ama[0].push_back({a,c});
        }else if(a%3==2){
            ama[1].push_back({a,c});
        }
    }
    string ans = "";
    for (int i = 0; i < n; i++) {
        ans.push_back('.');
    }
    for (auto e : ama[0]) {
        auto [a,c] = e;
        ans[a-1] = c;
    }
    for (auto e : ama[1]) {
        auto [a,c] = e;
        if(ans[a-2]==c)continue;
        if(ans[a-2]=='.'){
            ans[a-2]=c;
        }else{
            ans[a-1]=c;
        }
    }
    vector<ll> cnt(3);

    for (int i = 0; i < n; i++) {
        if(ans[i]=='.'){
            if(cnt[0]<=cnt[1]&&cnt[0]<=cnt[2]){
                ans[i] = 'R';
                cnt[0]++;
            }else if(cnt[1]<=cnt[0]&&cnt[1]<=cnt[2]){
                ans[i]= 'G';
                cnt[1]++;
            }else{
                ans[i]='B';
                cnt[2]++;
            }
        }else{
            if(ans[i]=='R')cnt[0]++;
            if(ans[i]=='G')cnt[1]++;
            if(ans[i]=='B')cnt[2]++;
        }
    }
    std::cout << ans << std::endl;
}