#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using pll = pair<ll,ll>;
using vll = vector<ll>;
using vi = vector<int>;
using pi = pair<int, int>;
using vpi = vector<pair<int, int>>;
using vai = vector<array<int, 3>>;

#define x first
#define y second
#define all(x) x.begin(), x.end()

void solve() {
    int n; cin >> n;
    for (int i = 1; i <= n; i++) {
        string in; cin >> in;
        string jo = "SZAM";
        if (i%15 == 0) {
            jo = "BUMM";
        } else if (i%5 == 0) {
            jo = "BAMM";
        } else if (i%3 == 0) {
            jo = "BIMM";
        } if (in != jo) {
            cout << i;
            return;
        }
    } cout << 0;
}

int main() {
	ios::sync_with_stdio(0);
    cin.tie(0);

    int t=1;
    //cin >> t;
    while (t--) {
        solve();
    }
}