Chef and his Crush

Chef wants to propose his crush through love letters. Given an array $A$ of size $N$. There is as a box placed on each index of the array, each box contains $A[i]$ number of love letters. He must choose at least 1 letter from every box according to conditions mentioned below: - From a box which is at Prime index, he must choose $X$ number of letters, where $X$ is non-prime. - From a box which