#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
using namespace std;
template <class T>
void vin(vector<T>& v, int n) {
  v.resize(n);
  for (int i = 0; i < n; ++i) {
    cin >> v[i];
  }
}
int main() {
  int n;
  cin >> n;
  vector<ll> a(n);
  ll ans = 0;
  for (int(i) = (0); (i) < (long long)(n); ++(i)) {
    cin >> a[i];
    ans += a[i] - 1;
  }
  cout << ans << endl;
}
