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

int main() {
	int n,a[110];
	bool f;
	cin>>n;
	for(int i = 1; i <= n; i++) {
		cin>>a[i];
	}

	f = false;
	for(int i = 1; i <= n - 2; i++) {
		if(a[i] >= 90&&a[i+1]>=90&&a[i+2]>=90) {
			cout<<"Y";
			f = true;
			break;
		}
	}

	if(!f) cout<<"N";




	return 0;
}

/**************************************************************
	Problem: 2084
	User: admin
	Language: C++
	Result: Accepted
	Time:64 ms
	Memory:2072 kb
****************************************************************/