Problem:
Score : 100 points

Problem Statement

Shichi-Go-San (literally "Seven-Five-Three") is a traditional event in a certain country to celebrate the growth of seven-, five- and three-year-old children.

Takahashi is now X years old. Will his growth be celebrated in Shichi-Go-San this time?

Constraints

1 ≤ X ≤ 9

X is an integer.

Input

Input is given from Standard Input in the following format:

X

Output

If Takahashi's growth will be celebrated, print YES; if it will not, print NO.

Sample Input 1

5

Sample Output 1

YES

The growth of a five-year-old child will be celebrated.

Sample Input 2

6

Sample Output 2

NO

See you next year.

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
 
namespace AtCoder
{
    class Program
    {
 
        static void Main()
        {
            //ここから
 
            int x = ReadLineToInt();
            string ans = x == 3 || x == 5 || x == 7 ? "YES" : "NO";
 
            Console.WriteLine(ans);
            Console.ReadKey();
        }
 
 
        static public void Swap<T>(ref T a,ref T b) { T temp = a;a = b;b = temp; }
        static public long GCD(int a, int b){ return b != 0 ? GCD(b, a % b) : a;}
        static public long LCM(int a, int b){ return (long)a * b / GCD(a, b); }
 
 
 
        
        static public string ReadLineToString(){return Console.ReadLine();}
        static public int ReadLineToInt(){return int.Parse(Console.ReadLine());}
        static public long ReadLineToLong() { return long.Parse(Console.ReadLine()); }
        static public string[] ReadLineToStringArray(){return Console.ReadLine().Split(' ').ToArray();}
        static public int[] ReadLineToIntArray(){return Console.ReadLine().Split(' ').Select(int.Parse).ToArray();}
        static public long[] ReadLineToLongArray() { return Console.ReadLine().Split(' ').Select(long.Parse).ToArray(); }
        static public List<string> ReadLineToStringList(){return Console.ReadLine().Split(' ').ToList();}
        static public List<int> ReadLineToIntList(){return Console.ReadLine().Split(' ').Select(int.Parse).ToList();}
        static public List<long> ReadLineToLongList() { return Console.ReadLine().Split(' ').Select(long.Parse).ToList(); }
    }
    
}