#include <bits/stdc++.h>
using namespace std;
int main()
{ int a;
 cin>>a;
 if(a>0&&a<100) {
 	cout<<"yes"<<endl;
 }

	return 0;
}

/**************************************************************
	Problem: 1641
	User: ccccccccccx
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/