#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:6 ms
	Memory:2072 kb
****************************************************************/