PolandBall is a young, clever Ball. He is interested in prime numbers. He has stated a following hypothesis: "There exists such a positive integer n that for each positive integer m number n·m + 1 is a prime number".

Unfortunately, PolandBall is not experienced yet and doesn't know that his hypothesis is incorrect. Could you prove it wrong? Write a program that finds a counterexample for any $*n*$.

Input

The only number in the input is $*n*$ ($1 ≤ *n* ≤ 1000$) — number from the PolandBall's hypothesis.

Output

Output such $*m*$ that $*n*·*m* + 1$ is not a prime number. Your answer will be considered correct if you output any suitable $*m*$ such that $1 ≤ *m* ≤ 10^{3}$. It is guaranteed the the answer exists.

Note

A prime number (or a prime) is a natural number greater than $1$ that has no positive divisors other than $1$ and itself.

For the first sample testcase, $3·1 + 1 = 4$. We can output $1$.

In the second sample testcase, $4·1 + 1 = 5$. We cannot output $1$ because $5$ is prime. However, $*m* = 2$ is okay since $4·2 + 1 = 9$, which is not a prime number.