I'm a little confused...why did he use base 36 instead of base 26? Aren't there only 26 letters we need to convert to numbers?
by convention in base 36, numbers can be represented by [0-9] and [a-z]. 1(36)=1(10) a(36)=10(10) and z(36)=36(10).
z(36) = 35(10), actually ;-)