#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

int main(){
    ll n, k;
    cin >> n >> k;

    vector<pair<ll, ll>> a(k);
    rep(i, k){
        ll A;
        char c;
        cin >> A >> c;
        a[i].fi = A;
        if(c=='R'){
            a[i].se = 0;
        }else if(c=='G'){
            a[i].se = 1;
        }else{
            a[i].se = 2;
        }
    }
    sort(all(a));

    ll m = n + (3 - n%3)%3;
    vector<ll> color(m+1, -1);
    ll now = 0;
    for(ll i=1; i<=m; i+=3){
        vector<bool> used(3, false);
        rep(j, 3){
            if(i+j == a[now].fi){
                if(used[a[now].se]){
                    rep(l, 3){
                        if(!used[l]){
                            used[l] = true;
                            color[i+j] = l;
                            break;
                        }
                    }
                }else{
                    color[i+j] = a[now].se;
                    used[color[i+j]] = true;
                }
                now++;
            }else{
                rep(l, 3){
                    if(!used[l]){
                        used[l] = true;
                        color[i+j] = l;
                        break;
                    }
                }
            }
        }
    }

    char x[3] = {'R', 'G', 'B'};
    for(ll i=1; i<=n; i++) cout << x[color[i]];
    cout << endl;
}