#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <math.h>

int main()
{
	enum SUCCESS
	{
		NONE,
		YES,
		NO,
	};

	int turn = 0;
	int nums[10] = { 0 };
	int isExist = false;

	for (int i = 0;i < turn;i++)
	{
		char str[10] = "";
		int num[4] = {0};
		for (int j = 0;j < 4;j++)
		{
			scanf("%d", &num[i]);
		}
		
		scanf("%s", str);
		if (str == "YES")
		{
			for (int j = 0;j < 4;j++)
			{
				if (nums[num[j]] < YES)
				{
					nums[num[j]] = YES;
				}
			}
			isExist = true;
		}
		else
		{
			for (int j = 0;j < 4;j++)
			{
				if (nums[num[j]] < NO)
				{
					nums[num[j]] = NO;
				}
			}
		}
	}

	if (isExist)
	{
		for (int i = 0;i < 10;i++)
		{
			if (nums[i] == YES)
			{
				printf("%d", i);
				return 0;
			}
		}
	}
	else
	{
		for (int i = 0;i < 10;i++)
		{
			if (nums[i] == 0)
			{
				printf("%d", i);
				return 0;
			}
		}
	}

	return 0;
}