#include<bits/stdc++.h>
using namespace std;
int main(){
    int m;
    cin>>m; 
    if(m>=90){
        cout<<"yes";
    }
}
/**************************************************************
	Problem: 1301
	User: yangjunwen
	Language: C++
	Result: Accepted
	Time:8 ms
	Memory:2072 kb
****************************************************************/