class Program
    {
        static void Main()
        {
            MySet<string> hashSet = new MySet<string>();
            while (true)
            {
                string input = Console.ReadLine();
                hashSet.Add(input);
            }
        }
    }
    class MySet<T>
    {
        private List<T>[] items = new List<T>[100];

        public void Add(T item)
        {
            int index = this.GetIndex(item.GetHashCode());

            if (this.Contains(item, index))
            {
                return;
            }

            if (items[index] == null)
            {
                items[index] = new List<T>();
            }

            items[index].Add(item);
        }

        public bool Contains(T item)
        {
            int hashCode = item.GetHashCode();
            int index = this.GetIndex(hashCode);
            return this.Contains(item, index);
        }

        private int GetIndex(int hashcode)
        {
            return Math.Abs(hashcode % items.Length);
        }

        private bool Contains(T value, int index)
        {
            if (this.items[index] != null)
            {
                foreach (T item in this.items[index])
                {
                    if (item.Equals(value))
                    {
                        return true;
                    }
                }
            }

            return false;
        }
    }