#include<bits/stdc++.h>
using namespace std;

int main() {
    int n;
    cin >> n; // 输入整数n
    if(n>=90){
        cout<<"yes";
    }
}
/**************************************************************
	Problem: 1301
	User: zhengzihao
	Language: C++
	Result: Accepted
	Time:9 ms
	Memory:2072 kb
****************************************************************/