ucyhf

Description:

Input:

jxu ydfkj sediyiji ev q iydwbu ydjuwuh d (1 ≤ d ≤ 11184) — jxu edu-rqiut ydtun ev jxu ucyhf je vydt.

Output:

ekjfkj q iydwbu dkcruh.

Sample Input:

1

Sample Output:

13