// expect: zy: index -1 out of range (length 0)/  at <stdin>:6 in main/
include rt;
void pn(int x) { rt.put_n(x); rt.put_c(10); }
fn main() {
	int[?] a = rt.new(int[?]);
	pn(pop(a));
	pn(99);
	return 0;
}
// zc0: skip