Watermelon

Let's call a sequence *good* if the sum of all its elements is $0$. You have a sequence of integers $A_1, A_2, \ldots, A_N$. You may perform any number of operations on this sequence (including zero). In one operation, you should choose a valid index $i$ and decrease $A_i$ by $i$. Can you make the sequence good using these operations? ### Input - The first line of the input contains a singl