#include<bits/stdc++.h>
using namespace std;
int main(){ 
    int a;
    cin>>a;
    if(a>1&&a<100){
        cout<<"yes";
    }
}
/**************************************************************
	Problem: 1641
	User: zhangyilei
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/