{
    (_div)(_zq)
        /(gcd)
            (_a)(_b)
                /
                    /
                        [_a]
                    /
                        /
                            /
                                [_b]
                            /
                                [_a]
                            [_div]
                        [second]
                    [gcd]
                /
                    [_b]
                /[_a][_zq]
        [YC]
|
    _gcd
}