//ww:run-exit 119
package main;
type tnode = struct { v: i64, kids: []tnode };
export fn main() i32 = {
	let inner: []tnode = [];
	append(inner, tnode { v = 7, kids = [] });
	append(inner, tnode { v = 9, kids = [] });
	let xs: []tnode = [];
	append(xs, tnode { v = 1, kids = inner });
	append(xs, xs[0].kids...);
	if (len(xs) != 3) { return 1; };
	if (xs[0].v != 1 || xs[1].v != 7 || xs[2].v != 9) { return 2; };
	return (81 + xs[1].v * 2 + xs[2].v * 2 + (len(xs): i64) * 2): i32;
};