// expect: 4/4/4/4/3/2/
include rt;
void pn(int x) { rt.put_n(x); rt.put_c(10); }
fn main() {
	int[?] a = {1, 2};
	push(a, 3); a.push(4);
	pn(len(a)); pn(cap(a)); pn(a[3]);
	pn(pop(a)); pn(a.pop()); pn(a.len());
	return 0;
}
// zc0: skip