input   = [5, 2, 9, 1, 7, 3, 8, 4, 6, 0]
sorted  = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
index of 7 = 7
index of 99 = -1
gcd(48, 36) = 12
sum     = 15
max     = 9
reduce  = 10
sqrt 2  = 1.4142135623730951
