#include<iostream>
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
****************************************************************/