The competition rules say: You are not eligible to receive any Prize in the Competition if you are a resident of a country designated by the United States Treasury's Office of Foreign Assets Control.
Could you please list these designated countries or clarify what list you are referring to?
I tried to find out it myself but failed: US Treasury’s Office website does not list such countries. The Office of Foreign Assets Control (OFAC) does not maintain a specific list of countries that U.S. persons cannot do business with.
It also looks like Specially Designated Nationals list does not list countries, only persons, entities, vessels and aircrafts.
which means unfortunately residents of these countries would not be eligible: the Balkans, Belarus, Burma, Cote D’Ivoire (Ivory Coast), Cuba, Democratic Republic of Congo, Iran, Iraq, Liberia, North Korea, Sudan, Syria, and Zimbabwe.
Country-related sanctions vary, so as noted on the website you can check specific programs from that list:
U.S. sanctions programs vary in scope. Some are broad-based and oriented geographically (i.e. Cuba, Iran). Others are “targeted” (i.e. counter-terrorism, counter-narcotics) and focus on specific individuals and entities. These programs may encompass broad prohibitions at the country level as well as targeted sanctions. Due to the diversity among sanctions, we advise visiting the “Sanctions Programs and Country Information” page for information on a specific program.