We are given a sequence A = {a1, a2, ... , an} which is index wise sum of two sequences B = {b1, b2, ... , bn} and C = {c1, c2, ... ,cn}.
i.e. a1 = b1 + c1, a2 = b2 + c2 , ... , an = bn + cn
B is non decreasing and C is non increasing.
Find the minimum possible value of abs(b1) + abs(b2) + ... + abs(bn) + abs(c1) + abs(c2) + ... + abs(cn).
Constraint — array size <= 2e5, -1e8 < a[i] < 1e8.
arc123_d