during research property great common divisor GCD set number Ildar famous mathematician introduce brand new concept weaken common divisor WCD list pair integersfor give list pair integer a_1 b_1 a_2 b_2 a_n b_n WCD arbitrary integer great 1 divide element pair WCD exist listsfor example list look like 12 15 25 18 10 24 wcd equal 2 3 5 6 number strictly great 1 divide number pairyoure currently pursue phd degree Ildars mentorship that s problem delegate your task calculate WCD efficiently