The problem is you have an array size N with N (1<=N<=1000) , ai and reorder array to have the amount of a[i]<a[i+1] is maximum

example:

Test 1: Input: 5 2 4 1 3 5 Output: 4

(now you sort it is 1 2 3 4 5)

Test 2: Input: 6 1 1 3 4 2 2 Output: 4

(now you sort it is 1 2 3 4 1 2)