static void Main()
{
HashTable<int, string> hashTable = new HashTable<int, string>();
for (int i = 0; i < 10; i++)
{
hashTable.Add(i, "element: " + i);
}
Console.WriteLine(hashTable[5]);
Console.WriteLine(hashTable.Find(3));
Console.WriteLine(hashTable.Contain(11));
hashTable.Remove(7);
hashTable.Remove(5);
Console.WriteLine(hashTable.Keys.Count());
}