#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: cyp
	Language: C++
	Result: Accepted
	Time:6 ms
	Memory:2072 kb
****************************************************************/