#include <iostream>

using namespace std;

int f(int i)
{
    cout<<i;
    return 0;
}

int main()
{
    int n;
    cin>>n;
    for(int i=1;i<=n;++i)
    {
        string s;
        cin>>s;
        if(s=="SZAM" and (i%3==0 or i%5==0)) return f(i);
        if(s=="BIMM" and i%3!=0) return f(i);
        if(s=="BAMM" and i%5!=0) return f(i);
        if(s=="BIMM" and (i%3!=0 or i%5!=0)) return f(i);
    }

    return 0;
}