gcd(38,27) = 1
gcd(63,24) = 3
gcd(64,15) = 1
gcd(55,14) = 1
gcd(63,36) = 9
gcd(16,72) = 8
gcd(56,59) = 1
gcd(90,98) = 2
gcd(22,52) = 2
gcd(49,35) = 7