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

using ll = long long;
using VI = vector<int>;
using VVI = vector<vector<int>>;
using VVVI = vector<vector<vector<int>>>;
using VL = vector<ll>;
using VVL = vector<vector<ll>>;
using VVVL = vector<vector<vector<ll>>>;
using VD = vector<double>;
using VVD = vector<vector<double>>;
using VVVD = vector<vector<vector<double>>>;
using VB = vector<bool>;
using VVB = vector<vector<bool>>;
using P = pair<int, int>;
using VP = vector<P>;

#define REP(i, n) for (int i = 0; i < (int)(n); i++)
#define FOR(i, a, b) for (ll i = a; i < (ll)(b); i++)
#define ALL(a) (a).begin(),(a).end()

constexpr int INF = 1001001001;
constexpr ll LINF = 1001001001001001001ll;
constexpr int DX[] = {1, 0, -1, 0};
constexpr int DY[] = {0, 1, 0, -1};

template< typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {return a < b && (a = b, true); }
template< typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {return a > b && (a = b, true); }

const ll MOD = 1000000007;

int main() {
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int N;
    cin >> N;
    VI A(N);
    REP(i, N) cin >> A[i];
    sort(ALL(A));
    ll ans = 1, c = 1;
    REP(i, N) {
        if (i > 0 && A[i] == A[i - 1]) c++;
        else c = 1;
        ans = ans * (i + 1) / c;
    }
    cout << ans << endl;
}