#include<bits/stdc++.h>
using namespace std;
int main(){
	int a;
	cin>>a;
	if(a>1&&a<100){
		cout<<"yes";
	}
} 
/**************************************************************
	Problem: 1641
	User: caiqiaoxi
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/