description 문제 history 제출 현황 question_mark 질문 how_to_vote 투표 #8076 upload 48 done 24 how_to_reg 18 gcd(x,y)=a, x+y=b timer 1s memory 1024MB keyboard_tab_rtl chevron_left 491 492 493 494 495 496 497 498 499 500 chevron_right keyboard_tab