#include<bits/stdc++.h>
using namespace std;
int main(){
	int a;
	cin>>a;
	if ((a>1)&&(a<100)) cout<<"yes";
}

/**************************************************************
	Problem: 1641
	User: huangsiyuan
	Language: C++
	Result: Accepted
	Time:7 ms
	Memory:2072 kb
****************************************************************/