Age Threshold

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem Statement

Given an integer age $a$. A person meets the required age when $a\ge18$. Determine whether the threshold is met.

Input

A single line contains the integer age $a$, where $0\le a\le150$.

Output

Print YES if $a\ge18$; otherwise print NO.

Subtasks

• Subtask 1 (20 points): $0\le a\le 30$.
• Subtask 2 (30 points): $0\le a\le 80$.
• Subtask 3 (50 points): $0\le a\le 150$.

Examples

Example 1

Input

17

Output

NO

Explanation

The age is 17. Comparing it with the threshold 18 gives a < 18, so the output is NO.

Example 2

Input

18

Output

YES

Explanation

The age is 18. Comparing it with the threshold 18 gives a >= 18, so the output is YES.