public void TestChar()
 {
     var stack = new Stack<char>();
     stack.Push('v');
     stack.Push('n');
     Assert.AreEqual('n', stack.Pop());
     Assert.AreEqual('v', stack.Pop());
 }
 static void Main(string[] args)
 {
     Stack stack = new Stack();
     for (int i = 1; i < 10; ++i)
     {
         stack.Push(i);
     }
     for (int i = 1; i < 10; ++i)
     {
         Console.WriteLine(stack.Pop());
     }
     Console.ReadKey();
 }