#include <bits/stdc++.h>
using namespace std;
//using namespace std::chrono;
#define pii pair<int,int>
#define pb push_back
#define vi vector<int>
#define vb vector<bool>
#define vl vector<ll>
#define vvi vector<vi>
#define vvb vector<vb>
#define vvl vector<vl>
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#define fScan {ios_base::sync_with_stdio(false); cin.tie(NULL);}
#define rep(i, a, b) for(int i = a; i < (b); i++)
#define REP(i, n) for(int i = 0;i <(n); i++)
using ll = long long;
using ld = long double;
ll mod = 1000000007;
const char ny = '\n';
bool prime(ll a) {
if (a==1) return 0;
for (int i=2;i*i<=a;++i)
{
if (a%i==0) return 0;
}
return 1;
}
ll gcd(ll a,ll b) {
if (b==0) return a;
return gcd(b,a%b);
}
ll lcm(ll a,ll b)
{
return a/gcd(a,b)*b;
}
ll min(int a, ll b) {
if(a< b) return a;
else return b;
}
void solve() {
int n;
cin >> n;
vector<string> k(n);
int ans = 0;
for(int i = 0;i< n;i++ ) cin >> k[i];
for(int i = 1;i<= n;i++ ) {
if(i%15 == 0) {
if(k[i-1] != "BUMM") {
cout << i << endl;
return;
}
} else if(i%3 == 0) {
if(k[i-1] != "BIMM") {
cout << i << endl;
return;
}
} else if(i%5 == 0) {
if(k[i-1] != "BAMM") {
cout << i << endl;
return;
}
} else {
if(k[i-1] != "SZAM") {
cout << i << endl;
return;
}
}
}
cout << 0 << endl;
}
int main()
{
fScan
int t = 1;
//comment out if necessary
//cin>> t;
//auto start = high_resolution_clock::now();
while(t-- ) {
solve();
}
//auto end = high_resolution_clock::now();
//auto dur = duration_cast<milliseconds>(end-start);
//cout<< "runtime: " << dur.count() << " milliseconds" << '\n';
return 0;
}