#include <bits/stdc++.h>

using namespace std;

string genword(int x)
{
    if(x%15 == 0)
    {
        return "BUMM";
    }
    else if (x%5 == 0)
    {
        return "BAMM";
    }
    else if (x%3 == 0)
    {
        return "BIMM";
    }
    else
    {
        return "SZAM";
    }
}

int main()
{
    int n;
    string word;
    cin >> n;
    for(int i = 1; i < n+1;i++)
    {
       cin >> word;
       if(word != genword(i))
       {
           cout << i;
           break;
       }
    }
}