Guddu and his Mother

Guddu was participating in a programming contest. He only had one problem left when his mother called him for dinner. Guddu is well aware how angry his mother could get if he was late for dinner and he did not want to sleep on an empty stomach, so he had to leave that last problem to you. Can you solve it on his behalf? For a given sequence of positive integers $A_1, A_2, \ldots, A_N$, you are su