#include "testlib.h"
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ull=unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

set<string> ColorsSet = {
  "Red","Orange","Yellow","Green","Cyan","Blue","Violet"
};
vector<string> ColorsVector = {
  "Red","Orange","Yellow","Green","Cyan","Blue","Violet"
};

const string Heads = "ROYGCBV";
int CA[7]={};
int CB[7]={};

int main(){
  registerValidation();
  int N = inf.readInt();
  inf.readEoln();
  for(int i=0; i<N; i++){
    if(i!=0) inf.readSpace();
    string S = inf.readToken();
    assert(ColorsSet.count(S) != 0);
    CA[Heads.find(S.front())] += 1;
  }
  inf.readEoln();
  for(int i=0; i<N-1; i++){
    if(i!=0) inf.readSpace();
    string S = inf.readToken();
    assert(ColorsSet.count(S) != 0);
    CB[Heads.find(S.front())] += 1;
  }
  inf.readEoln();
  inf.readEof();
  int sumabs = 0;
  for(int t=0; t<7; t++) sumabs += abs(CA[t]-CB[t]);
  assert(sumabs==1);
  for(int t=0; t<7; t++){
    if(CA[t] != CB[t]){
      printf(ColorsVector[t].c_str());
    }
  }
  return 0;
}