Balls

Time Limit : 1 seconds Memory Limit : 10MB

Tracy has been dreaming of becoming a basketball player for many years. But considering her current height... However, Tracy still loves basketball. One day she saw a basketball game: There were n big baskets with unlimited height but small width which only allows one ball to pass.

A player can shoot a basketball into arbitrary baskets. Basketballs are numbered from 1. The player should obey the following rules:

1. Balls with smaller numbers should be put under balls with larger numbers.
2. The sum of two neighboring balls' number should be a prime.
3. You can't shoot the basketball numbered i unless the basketball numbered i - 1 has already been successfully shot into one of the baskets.

The winner is the person who shoots most number of basketballs.
All the balls numbered from 1 to n should be shot into baskets.
Tracy wanted to win the game. She wanted to know how many balls can be put at most?

Input:

The input file contains several test cases. For each test case:
only one line contains one number n (0<= n < 16).

Output:

For each test case, output one number m, the maximal number of balls, on a separate line.

Sample Input:

1

Sample Output:

4