#include <iostream>
#include <string>

using namespace std;

int main()
{
	int a,b;
	cin >> a;
	if(a < 1)
	{
		cout << "Incorrect position." << endl;
		return 0;
	}
	for(int i = 1; i < a; i++)
	{
		cin >> b;
		if(b == -1)
		{
			cout << "Incorrect position." << endl;
			return 0;
		}
	}
	cin >> b;
	if(b == -1)
	{
		cout << "Incorrect position." << endl;
		return 0;
	}
	cout << "At the position " << a << " there is a(n) " << b << "." << endl;

}