#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using pl = std::pair<long long, long long>;
using mint = atcoder::modint1000000007;
//using mint = atcoder::modint998244353;
#define rep(i, srt, end) for (long long i = (srt); i < (long long)(end); i++)
#define all(v) (v).begin(), (v).end()
#define dump(var)  do{ if(debug::enable) { std::cerr << #var << " : "; debug::print(var); } } while(0);
constexpr int di[4] = {1, -1, 0, 0};
constexpr int dj[4] = {0, 0, 1, -1};
constexpr long long inf = 1LL<<60;
template<typename T> inline void chmax(T &a, T b) { a = std::max(a, b); };
template<typename T> inline void chmin(T &a, T b) { a = std::min(a, b); };
template<typename T> void vprint(const std::vector<T>& v) { for(int i = 0; i < v.size(); i++) { std::cout << v[i] << (i == v.size()-1 ? "\n" : " "); } }
template<typename T> void vprintln(const std::vector<T>& v) { for(int i = 0; i < v.size(); i++) { std::cout << v[i] << "\n"; } }
template<int M> void vprint(const std::vector<atcoder::static_modint<M>>& v) { for(int i = 0; i < v.size(); i++) { std::cout << v[i].val() << (i == v.size()-1 ? "\n" : " "); } }
template<int M> void vprintln(const std::vector<atcoder::static_modint<M>>& v) { for(int i = 0; i < v.size(); i++) { std::cout << v[i].val() << "\n"; } }
namespace debug {    
    #if defined(ONLINE_JUDGE)
    const bool enable = false;
    #else
    const bool enable = false;
    #endif
    template<typename T> void push(const T& e) { std::cerr << e; }
    template<int M> void push(const atcoder::static_modint<M>& e) { std::cerr << e.val(); }
    template<typename T1, typename T2> void push(const std::pair<T1, T2>& e) { std::cerr << "("; push(e.first); std::cerr << ","; push(e.second); std::cerr << ")"; }   
    template<typename T1, typename T2, typename T3> void push(const std::tuple<T1, T2, T3>& e) { std::cerr << "("; push(get<0>(e)); std::cerr << ","; push(get<1>(e)); std::cerr << ","; push(get<2>(e)); std::cerr << ")"; }   
    template<typename T> void print(const T& e) { push(e); std::cerr << "\n"; }
    template<typename T> void print(const std::vector<T>& v) { for(int i = 0; i < v.size(); i++) { push(v[i]); std::cerr << " "; } std::cerr << "\n"; }
    template<typename T> void print(const std::vector<std::vector<T>>& v) { std::cerr << "\n"; for(int i = 0; i < v.size(); i++) { std::cerr << i << ": "; print(v[i]); } }
};

void solve() {
    ll n, k;
    cin >> n >> k;
    vector<ll> a(k);
    vector<string> c(k);
    rep(i, 0, k) cin >> a[i] >> c[i];
    dump(a);
    dump(c);
    vector<char> v(n, '?');
    rep(i, 0, k) v[a[i]-1] = c[i].front();
    dump(v);
    string ans;
    ll r = 0, g = 0, b = 0;
    rep(i, 0, n) {
        if(v[i] != '?' && r == g && r == b) {
            if(v[i] == 'R') {
                r++;
                ans.push_back('R');
            } else if(v[i] == 'G') {
                g++;
                ans.push_back('G');
            } else if(v[i] == 'B') {
                b++;
                ans.push_back('B');
            } 
        } else {
            ll mx = max({r, g, b});
            if(r != mx) {
                r++;
                ans.push_back('R');
            } else if(g != mx) {
                g++;
                ans.push_back('G');
            } else {
                b++;
                ans.push_back('B');
            }
        }
    }    
    cout << ans << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}