#include<bits/stdc++.h>
using namespace std;
int a;
int main(){
	cin>>a;
	if(a>1&&a<100) cout<<"yes";
	return 0;
}
/**************************************************************
	Problem: 1641
	User: zhangziang
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/