Problem Description

Welcome to CODE FESTIVAL 2016! To celebrate this contest, find a string $ s $ that satisfies the following conditions:

• The length of $ s $ is between $ 1 $ and $ 5000 $ inclusive.
• $ s $ consists only of uppercase English letters.
• $ s $ contains the substring "FESTIVAL" exactly $ K $ times as a subsequence. In other words, there are exactly $ K $ sets $ (i_0, i_1, ..., i_7) $ such that $ 0 <= i_0 < i_1 < ... < i_7 <= |s|-1 $ and $ s[i_0]='F', s[i_1]='E', ..., s[i_7]='L' $.

It can be proven that a solution always exists under the given constraints. If multiple solutions are possible, you may output any one.

Input Format

The input is given from the standard input in the following format:

$ K $

Output Format

Output a string that satisfies the given conditions.

Sample Input and Output

Sample Input #1

7

Sample Output #1

FESSSSSSSTIVAL

Sample Input #2

256

Sample Output #2

FFEESSTTIIVVAALL

Notes/Hints

Constraints

• $ 1 <= K <= 10^{18} $

见题面 Input 部分

见题面 Output 部分