They are Hong Chung Song and Choe Kwang of Pyongyang Secondary School No. 1.

The Olympiad held in Argentina brought together more than 540 students from 100 countries and regions.

Presented there were math problems in the fields of theory of numbers, algebra, geometry, combination and functional equation.

Hong and Choe solved difficult problems requiring high concentration and thinking power to win gold medals.

They returned home by air Thursday.