[ACM-ICPC][Asia - Seoul] 4723 - Ducci Sequence
A Ducci sequence is a sequence of n-tuples of integers. Given an
n-tuple of integers
(a1, a2, ... , an), the next n-tuple
in the sequence is formed by taking the absolute differences of
neighboring integers:
(a1, a2, ... , an) (| a1 - a2|,| a2 - a3|, ... ,|...
