struct cnt {
	int n;
	static int make() { return 3; }
	int get() { return this.n; }
};
fn main() {
	[]int xs = new([]int);
	push(xs, 4); push(xs, 5);
	put_n(len(xs)); put_c(10);
	put_n(pop(xs)); put_c(10);
	put_n(cnt.make()); put_c(10);
	return 0;
}