#include<bits/stdc++.h>
using namespace std;
int main(){
	int m;
	cin>>m; 
	if(m>=90){
		cout<<"yes";
	}
}
/**************************************************************
	Problem: 1301
	User: wangyiyang
	Language: C++
	Result: Accepted
	Time:10 ms
	Memory:2072 kb
****************************************************************/