// Bimm, bamm, bumm.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>

using namespace std;

int i, n;
string s;

int main()
{
    cin >> n;

    for (i = 1; i <= n; ++i)
    {
        cin >> s;
        if (i % 3 == 0 && i % 5 == 0 && s[1]!='U')
        {
            cout << i;

            return 0;
        }
        if (i % 3==0 && i % 5 != 0 && s[1] != 'I')
        {
            cout << i;

            return 0;
        }
        if (i % 5==0 && i % 3 != 0 && s[1] != 'A')
        {
            cout << i;

            return 0;
        }
        if (i % 3 != 0 && i % 5 != 0 && s[1] != 'Z')
        {
            cout << i;

            return 0;
        }
    }
    
    cout << "0";

    return 0;
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file