#include<iostream>
using namespace std;
int main(){
	int n,a[100],i,d=0;
	cin>>n;
	for(i=0;i<n-1;i++){
		cin>>a[i];
	}
	for(i=0;i<n-1;i++){
		if(a[i]>=90){
			d++;
		}
	}
	for(i=0;i<n-1;i++){
		if(n<60){
			cout<<"no";
			return 0;
		}
	}
	if(d>=5){
		cout<<"1";
	}else if(d==3||d==4){
		cout<<"2";
	}else if(d==2){
		cout<<"3";
	}
	
}
/**************************************************************
	Problem: 1429
	User: panyuchen
	Language: C++
	Result: Wrong Answer
****************************************************************/