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

/**************************************************************
	Problem: 1301
	User: zhengzihao3
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/