#include<bits/stdc++.h>
using namespace std;
int main(){
    int a;
	cin>>a;
	if(a>1&&a<100)
	{
	   cout<<"yes";	
	} 
}
/**************************************************************
	Problem: 1641
	User: xuezihong1
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/