#include<bits/stdc++.h>
using namespace std;
int main(){
	int a;
	cin>>a;
	if(a>=90){
		cout<<"yes";
	}
	return 0;
}

/**************************************************************
	Problem: 1301
	User: huangcanwu
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/