Sieve of Eratosthenes

The sieve of Eratosthenes finds every prime that is not greater than $N$. The procedure is this.

1. Write down every integer from $2$ to $N$.
2. Find the smallest number that is not crossed out yet and call it $P$. $P$ is prime.
3. Cross out $P$ and every multiple of $P$ that is not crossed out yet, in increasing order.
4. If some number is still not crossed out, go back to step 2.

Given $N$ and $K$, find the $K$-th number that is crossed out.

The input holds several test cases. Each line has two integers $N$ and $K$ separated by a space ($2 \le K < N \le 1000$).

Process every line until the end of the input.

For each test case, print the $K$-th number that is crossed out on its own line.