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