SP27307 ALTSEQ - Alternating Sequences

Given an array a of N integers a1, a2, a3, ... aN you have to find the longest alternating sub-sequence of this array . An alternating sequence b1, b2 ... bk, k>=1 is a sequence that has the 2 following properties: 1.|b1|

The first line contains a single integer N, denoting the size of the array. The next line contains N integers , denoting the array a.

Print a single integer - the length of the longest alternating sub-sequence.