Problem:
Score: 300 points

Problem Statement

We have N voting papers. The i-th vote (1 \leq i \leq N) has the string S_i written on it.

Print all strings that are written on the most number of votes, in lexicographical order.

Constraints

1 \leq N \leq 2 \times 10^5

S_i (1 \leq i \leq N) are strings consisting of lowercase English letters.

The length of S_i (1 \leq i \leq N) is between 1 and 10 (inclusive).

Input

Input is given from Standard Input in the following format:

N
S_1
:
S_N

Output

Print all strings in question in lexicographical order.

Sample Input 1

7
beat
vet
beet
bed
vet
bet
beet

Sample Output 1

beet
vet

beet and vet are written on two sheets each, while beat, bed, and bet are written on one vote each. Thus, we should print the strings beet and vet.

Sample Input 2

8
buffalo
buffalo
buffalo
buffalo
buffalo
buffalo
buffalo
buffalo

Sample Output 2

buffalo

Sample Input 3

7
bass
bass
kick
kick
bass
kick
kick

Sample Output 3

kick

Sample Input 4

4
ushi
tapu
nichia
kun

Sample Output 4

kun
nichia
tapu
ushi

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
using static kyoupuro.Input;
using static kyoupuro.MyMath;
using static kyoupuro.Modular;

namespace kyoupuro {

    class MainClass {

        public static void Main() {
            int N = NextInt;
            var table = new Dictionary<string, int>();
            for (int i = 0; i < N; i++) {
                var line = Console.ReadLine();
                if (table.ContainsKey(line)) {
                    int tmp = table[line];
                    table[line] = tmp + 1;
                } else {
                    table[line] = 1;
                }
            }

            int maximum = table.Values.Max();
            var set = new SortedSet<string>(StringComparer.Ordinal);
            foreach(var item in table) {
                if(item.Value == maximum) {
                    set.Add(item.Key);
                }
            }
            Console.WriteLine(string.Join("\n", set));
        }
    }

    class MyMath {
        public static long Gcd(long a, long b) {
            return b == 0 ? a : Gcd(b, a % b);
        }

        public static long Sqrt(long n) {
            if (n < 0) return 0;
            long a = 0, tmp = 0, b = 0;
            for (int i = 62; i >= 0; i -= 2) {
                tmp = (b << 1) + 1 <= (n >> i) ? 1 : 0;
                a = a << 1 | tmp;
                n -= (((b << 1) + 1) * tmp) << i;
                b = (b << 1) + tmp + tmp;
            }
            return a;
        }

        public static long Nck(int n, int k) {
            if (k == 0) return 1;
            if (n == 0) return 0;
            return n * Nck(n - 1, k - 1) / k;
        }
    }

    class Modular {
        public const int mod = 1000000007;
        public readonly long value;
        public Modular(long value) { this.value = value; }
        public static implicit operator Modular(long a) {
            var m = a % mod;
            return new Modular((m < 0) ? m + mod : m);
        }
        public static Modular operator +(Modular a, Modular b) {
            return a.value + b.value;
        }
        public static Modular operator -(Modular a, Modular b) {
            return a.value - b.value;
        }
        public static Modular operator *(Modular a, Modular b) {
            return a.value * b.value;
        }
        private static Modular Pow(Modular a, int n) {
            switch (n) {
                case 0:
                    return 1;
                case 1:
                    return a;
                default:
                    var p = Pow(a, n / 2);
                    return p * p * Pow(a, n % 2);
            }
        }
        public static Modular operator /(Modular a, Modular b) {
            return a * Pow(b, mod - 2);
        }
        private static readonly List<int> facs = new List<int> { 1 };
        private static Modular Fac(int n) {
            for (int i = facs.Count; i <= n; ++i) {
                facs.Add((int)(Math.BigMul(facs.Last(), i) % mod));
            }
            return facs[n];
        }
        public static Modular Ncr(int n, int r) {
            return (n < r) ? 0
                 : (n == r) ? 1
                            : Fac(n) / (Fac(r) * Fac(n - r));
        }
        public static explicit operator int(Modular a) {
            return (int)a.value;
        }
    }

    public class PriorityQueue<T> {

        readonly List<T> _heap = new List<T>();
        readonly Comparison<T> _comparison;

        public PriorityQueue(Comparison<T> comparison) {
            _comparison = comparison;
        }

        public PriorityQueue() : this(Comparer<T>.Default.Compare) { }

        public PriorityQueue(IComparer<T> comparer) : this(comparer.Compare) { }

        public void Enqueue(T item) {
            _heap.Add(item);

            int childID = _heap.Count - 1;
            int parentID = (childID - 1) / 2;

            while (childID > 0 && _comparison(_heap[parentID], _heap[childID]) > 0) {
                Swap(parentID, childID);
                childID = parentID;
                parentID = (parentID - 1) / 2;
            }
        }

        public T Dequeue() {
            var first = _heap.First();
            _heap[0] = _heap.Last();
            _heap.RemoveAt(_heap.Count - 1);

            int parentID = 0;
            int childID = parentID * 2 + 2;
            if (childID >= _heap.Count || _comparison(_heap[childID], _heap[childID - 1]) > 0) childID--;

            while (childID < _heap.Count && _comparison(_heap[parentID], _heap[childID]) > 0) {
                Swap(parentID, childID);
                parentID = childID;
                childID = parentID * 2 + 2;
                if (childID >= _heap.Count || _comparison(_heap[childID], _heap[childID - 1]) > 0) childID--;
            }

            return first;
        }

        void Swap(int parent, int child) {
            var tmp = _heap[parent];
            _heap[parent] = _heap[child];
            _heap[child] = tmp;
        }

        public T Peek() { return _heap[0]; }
        public int Count => _heap.Count;
        public bool Any() { return _heap.Any(); }
        public List<T> Data => _heap;
    }

    public class UnionFind {
        public int[] Parents { get; set; }
        public UnionFind(int size) {
            Parents = Enumerable.Repeat(-1, size).ToArray();
        }

        public int Find(int num) {
            if (Parents[num] < 0) return num;

            Parents[num] = Find(Parents[num]);
            return Parents[num];
        }

        public int Size(int num) {
            return -Parents[Find(num)];
        }

        public bool Same(int a, int b) {
            return Find(a) == Find(b);
        }

        public void Unite(int a, int b) {
            int x = Find(a), y = Find(b);

            if (Size(x) > Size(y)) {
                Parents[x] += Parents[y];
                Parents[y] = x;
            } else {
                Parents[y] += Parents[x];
                Parents[x] = y;
            }
        }
    }

    class Input {
        static IEnumerator<string> enumerator = new string[] { }.AsEnumerable().GetEnumerator();

        public static string Line => Console.ReadLine();

        public static string[] StrArr => Line.Split(' ');

        public static int NextInt => int.Parse(NextWord());

        public static long NextLong => long.Parse(NextWord());

        public static List<int> IntList => StrArr.Select(int.Parse).ToList();

        public static List<long> LongList => StrArr.Select(long.Parse).ToList();

        public static string NextWord() {
            while (!enumerator.MoveNext()) {
                enumerator = StrArr.AsEnumerable().GetEnumerator();
            }
            return enumerator.Current;
        }
    }
}