#include<iostream>
#include<cstdio>
#include<cmath>
#include<string>
#include<cstring>
#include<algorithm>
#include<fstream>
#include<stdio.h>
#include<stdlib.h>
using namespace std;
char a;
int main()
{
	cin>>a;
	if(int(a)%2==0)cout<<"NO";
	else cout<<"yes";
	return 0;
}

谢谢大家