#include <stdio.h>
#include <string.h>

void main(void){
	//調べる数字は0～9の間の数字。
	int turn = 0;
	int input = scanf("%d\n",&turn);
	int targetNumber = 0;
	int pickUp[4];
	int numericList[10] = {0};
	int count = 0;
	
	for(int i = 0 ; i < turn ; i++ ){
		for(int j = 0 ; j < 4 ; j++ ){
			input = scanf("%d",&pickUp[j]);
		}
		char judge[10] = "a";
		input = scanf("%s",judge);
		if(strcmp(judge,"YES") == 0){
			count++;
			for(int j = 0 ; j < 4 ; j++ ){
				numericList[pickUp[j]] += 7;
			}
		}else{
			for(int j = 0 ; j < 4 ; j++ ){
				numericList[pickUp[j]]--;
			}
		}
	}
	targetNumber = -1;
	for(int i = 0 ; i < 10 ; i++){
		if(numericList[i] == 7*count){
			targetNumber = i;
			break;
		}
	}
	if(targetNumber == -1){
		for(int i = 0 ; i < 10 ; i++){
			if(numericList[i] == 0){
				targetNumber = i;
				break;
			}
		}
	}
	printf("%d",targetNumber);	
}