#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: chenmingyu
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/