#include<iostream>
using namespace std;
int main()
{
    int n,a,count=0;
    cin>>n;
    while(n--)
    {
        cin>>a;
        if(a==90)
            count++;
    }
    cout<<count<<endl;
    return 0;
}

/**************************************************************
	Problem: 2095
	User: admin
	Language: C++
	Result: Accepted
	Time:13 ms
	Memory:2072 kb
****************************************************************/