Hi there. I will be connecting via IAD, landing on United from Cancun at 16:20 and departing on South African Airways (SAA) at 17:40 (thus 80 minutes layover). I will have no checked-in luggage, only my carry-on. Will I still need to go through customs and passport control, or can I do an international connection and proceed to my SAA gate directly? Both tickets are separate, but I will have my boarding pass already printed from online for the SAA flight. Thanks.