//Aideen's Code for P31 {aideen[at]gmail[dot]com}
#include <iostream>
using namespace std;

const int MAX_N = 15 + 3;
int n, a[MAX_N];
long long fact[MAX_N];

int main() {
  cin >> n;
  for (int i=0; i<n; i++)
    cin >> a[i];
  
  fact[0] = 1;
  for (int i=1; i<=n; i++)
    fact[i] = i*fact[i-1];
  
  long long ans = 1;
  for (int i=0; i<n; i++) {
    ans += (a[i]-1)*fact[n-i-1];
    for (int j=i+1; j<n; j++)
      a[j] -= (a[j] > a[i]);
  }

  cout << ans << endl;
  return 0;
}