Passage: From there, Changchun passed to Balasagun and Shu River, and across that river to Talas and the Tashkent region, and then over the Syr Darya to Samarkand, where he halted for some months. Finally, through the Iron Gates of Termit, over the Amu Darya, and by way of Balkh and northern Afghanistan, Changchun reached Genghis' camp near the Hindu Kush.

Question: Where did Changchun reached?
Genghis' camp