## Problem Description

Given a number N, Jason will connect from the first prime number to the Nth prime to form a new number.

Unfortunately, Jason has gone crazy, and he will repeat operation:

1、delete the number in the even position;

2、delete the number in the odd position.

Now, Jason wants to know what the last number is.

For example, if N is equal to 6, the new number is 23571113.

After deleting the number in even position, the new number is 2511

After deleting the number in odd position, the new number is 51

After deleting the number in even position, the new number is 5

Therefore, the last number is 5.

## Input

The input will consist of a series of test cases, and each test case contains an integers N (N <= 20000).

## Output

For each test case, output what the last number is.

## Sample Input

6

## Sample Output

5