#include <stdio.h>
#include <stdlib.h>
#include <string.h>
extern int getchar_unlocked(void);
extern int putchar_unlocked(int);
#define gc(d)	(d)=getchar_unlocked()
#define	pc(d) putchar_unlocked(d)
#define REP(a,b) for(int a=0;a<(int)(b);++a)
static char *GETWORD(char* str) {char c;char *cp;cp=&str[0];gc(c);while(c!=EOF){if((c==' ')||(c=='\n'))break;*cp++=c;gc(c);}*cp='\0';return &str[0];}
#define GETLINE(str) do{char *p;fgets(str,sizeof(str),stdin);p=strchr(str,'\n');if(p)*p='\0';}while(0)
static int GETLINEINT(void) {char s[34];GETLINE(s);return atoi(s);}
// *********************
char color[7][7] ={"Red","Orange","Yellow","Green","Cyan","Blue","Violet"};
int	numb[255];
// *********************
int main( void ) {
	int	q;
	char	str[20];

	REP(i,255) numb[i]= 0; 
	q = GETLINEINT();
	REP(i,q) {
		GETWORD(str);
		numb[ str[0] - 'B' ]++;
	}
	q--;
	REP(i,q) {
		GETWORD(str);
		numb[ str[0] - 'B' ]--;
	}
	REP(i,255) if( numb[i] == 1 ) {
		int	c = i + 'B';
		if( c == 'R' ) {
			printf("Red");
		} else if( c == 'O') {
			printf("Orange");
		} else if( c == 'Y') {
			printf("Yellow");
		} else if( c == 'G') {
			printf("Green");
		} else if( c == 'C') {
			printf("Cyan");
		} else if( c == 'B') {
			printf("Blue");
		} else  {
			printf("Violet");
		}
		pc('\n');
		return 0;
	}
}