#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using vi = vector<int>;
using vl = vector<ll>;
using vpi = vector<pi>;
using vpl = vector<pl>;
#define fur(i, a, b) for(ll i = a; i <= (ll) b; ++i)
#define ruf(i, a, b) for(ll i = a; i >= (ll) b; --i)
#define fr first
#define sc second
#define mp make_pair
#define pb push_back
#define eb emplace_back
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define nl "\n"
const ll mod = 1e9L + 7;
const ll mxn = 3e5L + 5;
ll n;
pl p[mxn];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n;
fur(i, 1, n) {
cin >> p[i].fr;
p[i].sc = i;
}
sort(p + 1, p + n + 1);
ll a[n + 1];
fur(i, 1, n) {
a[p[i].sc] = i;
}
ll perm[n + 1];
iota(perm + 1, perm + n + 1, 1);
// fur(i, 1, n)
// cout << perm[i] << ' ';
// cout << nl;
ll res = 0;
do {
bool same = 1;
fur(i, 1, n) {
if(perm[i] != a[i]) {
same = 0;
break;
}
}
++res;
if(same)
break;
} while(next_permutation(perm + 1, perm + n + 1));
cout <<res << nl;
}
