pub mod complicated {
pub mod a {
pub fn a() {
    println!("a::a()");
}
}
pub mod b {
use super::a;
pub fn b() {
    a::a();
}
}
pub mod c {
pub mod d {
pub fn d() {
    println!("c::d::d()");
}
}
}
}
use self::complicated::{a, b, c};
fn main() {
    a::a();
    self::b::b();
    self::c::d::d();
}