#include <bits/stdc++.h>
using namespace std;
int main(){
int a;
cin>>a;
if(a>1&&a<100)cout<<"yes";
return 0;
}
/**************************************************************
	Problem: 1641
	User: ljl2
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/