Prime Lover

There is a farm containing trees numbered from $1$ to $N$. The owner of the farm believes in god, so he thinks that a tree can only be cut down if it's height is a **Prime number**. The height of the trees increase by $1$ unit every day. So every day he goes to the farm and starts cutting trees whose height is a prime number. If there are multiple such trees in a day, he cuts them down in increasi