using LIB;
using System;
using System.Linq;
using System.Text;
using System.Collections.Generic;

class Program
{
    public static IO IO = new IO();
    static void Main(string[] args)
    {
        int n = IO.INT();
        string[][] d = IO.STRING(n, ' ');
        int[] yes = new int[10];
        int[] no = new int[10];
        bool[] bl = new bool[10];
        int max = 0;
        for (int i = 0; i < n; i++)
        {
            int[] b;
            if (d[i][d[i].Length - 1] == "YES")
            {
                b = yes;
            }
            else
            {
                b = no;
            }
            for (int j = 0; j < d[i].Length - 1; j++)
            {
                b[int.Parse(d[i][j])]++;
            }
        }
        for (int i = 0; i < 10; i++)
        {
            if (no[i] != 0)
            {
                bl[i] = true;
            }
        }
        max = yes.Max();
        if (max == 0)
        {
            for (int i = 0; i < 10; i++)
            {
                if (no[i] == 0)
                {
                    IO.WRITE(i);
                    break;
                }

            }
        }
        else
        {
            for (int i = 0; i < 10; i++)
            {
                if (yes[i] == max && bl[i] == false)
                {
                    IO.WRITE(i);
                    break;
                }

            }
        }
        IO.FLUSH();
    }
}

namespace LIB
{
    public class IO
    {
        private const int WMAX = 1000;
        private StringBuilder S = new StringBuilder();
        private T R<T>(Func<string, T> f) { return f(Console.ReadLine()); }
        private T[] R<T>(Func<string, T> f, char c) { return STRING().Split(c).Select(f).ToArray(); }
        private T[] R<T>(Func<string, T> f, int l) { T[] r = new T[l]; for (int i = 0; i < l; i++) { r[i] = R(f); } return r; }
        private T[][] R<T>(Func<string, T> f, int l, char c) { T[][] r = new T[l][]; for (int i = 0; i < l; i++) { r[i] = R<T>(f, c); } return r; }
        private void W<T>(Func<T, string> f, T v, bool lf = true) { S.Append(f(v)); if (lf == true) { S.Append('\n'); } if (S.Length >= WMAX) { FLUSH(); } }
        public string STRING() { return R(s => s); }
        public string[] STRING(char c) { return R(s => s, c); }
        public string[] STRING(int l) { return R(s => s, l); }
        public string[][] STRING(int l, char c) { return R(s => s, l, c); }
        public int INT() { return R(int.Parse); }
        public int[] INT(char c) { return R(int.Parse, c); }
        public int[] INT(int l) { return R(int.Parse, l); }
        public int[][] INT(int l, char c) { return R(int.Parse, l, c); }
        public long LONG() { return R(long.Parse); }
        public long[] LONG(char c) { return R(long.Parse, c); }
        public long[] LONG(int l) { return R(long.Parse, l); }
        public long[][] LONG(int l, char c) { return R(long.Parse, l, c); }
        public double DOUBLE() { return R(double.Parse); }
        public double[] DOUBLE(char c) { return R(double.Parse, c); }
        public double[] DOUBLE(int l) { return R(double.Parse, l); }
        public double[][] DOUBLE(int l, char c) { return R(double.Parse, l, c); }
        public void WRITE(string s, bool lf = true) { W(v => v, s, lf); }
        public void WRITE(int s, bool lf = true) { W(v => v.ToString(), s, lf); }
        public void WRITE(long s, bool lf = true) { W(v => v.ToString(), s, lf); }
        public void WRITE(double s, bool lf = true) { W(v => v.ToString(), s, lf); }
        public void FLUSH() { Console.Write(S); S.Length = 0; }
    }
}