fn start_main() -> i64 {
    let empty: list<string> = [];
    if (join(empty, ",") not match "") { return 1; }
    let one: list<string> = ["مرحبا"];
    if (join(one, ",") not match "مرحبا") { return 2; }
    let parts: list<string> = ["a", "b", "c"];
    if (join(parts, ",") not match "a,b,c") { return 3; }
    if (join(parts, "") not match "abc") { return 4; }
    print(join(parts, ","));
    return 0;
}