#include <iostream>
#include <vector>
using namespace std;

int main()
{
    int n;
    cin >> n;
    vector <string> v(n + 1);
    for (int i = 1; i <= n; i++)
    {
        cin >> v[i];
    }
    for (int i = 1; i <= n; i++)
    {
        if(v[i] == "SZAM" && (i % 3 == 0 || i % 5 == 0))
        {
            cout << i;
            return 0;
        }
        else
        {
            if (v[i] == "BIMM" && i % 3 != 0)
            {
                cout << i;
                return 0;
            }
            else
            {
                if (v[i] == "BAMM" && i % 5 != 0)
                {
                    cout << i;
                    return 0;
                }
                else
                {
                    if (v[i] == "BUMM" && !(i % 3 == 0 && i % 5 == 0))

                    {
                        cout << i;
                        return 0;
                    }
                }
            }
        }
    }
    cout << 0;
    return 0;
}