Chef and Fixed Deposits

Chef wants to make a purchase. For this, he needs $X$ gold coins, but he has none at the moment. Chef has $N$ fixed deposits, the $i^{th}$ of which is worth $A_i$ coins. He wants to open the minimum number of these deposits so that he has at least $X$ coins. You have to tell Chef the minimum number of fixed deposits he must open in order to have $X$ coins, or say that this is impossible. ### In