public static void Main()
{
//create context action
context = new context();
int a = 2;
int b = 5;
action = new ConcreteStrategyAdd(a, b);
context.setStrategy(action);
// if(action == new ConcreteStrategyAdd)
// {
// context.setStrategy(action);
// System.Console.WriteLine("hello from instance");
// }
// return 0;
}