using System;

interface IA {
	void f();
}
class B<T> where T : IA, new(){
	public void f(int n)	{
		DateTime st = DateTime.Now;
		for (int i = 0; i < n; i++){
			T a = new T();
			a.f();
		}
		Console.WriteLine((DateTime.Now - st).Milliseconds + " msec");
	}
}

struct A : IA{
	public int n;
	public void f() { n++; }
}

class C{
	public void f(int n){
		DateTime st = DateTime.Now;
		for (int i = 0; i < n; i++){
			IA a = new A();
			a.f();
		}
		Console.WriteLine((DateTime.Now - st).Milliseconds + " msec");
	}
	public void fT<T>(T a) where T : IA {a.f();}
	public void f2(int n){
		DateTime st = DateTime.Now;
		for (int i = 0; i < n; i++){
			fT(new A());
		}
		Console.WriteLine((DateTime.Now - st).Milliseconds + " msec");
	}
}

public class Test{
	public static void Main(){
		int n = 20000000;
		B<A> b = new B<A>();
		b.f(n);
		C c = new C();
		c.f(n);
		c.f2(n);
	}
}