#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
const int mod = 1e9 + 7;
const ll INF = 1e18;
const int MAX = 1e6;
int main() {
  int n;
  cin >> n;
  vi a(n);
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  int f;
  for (int i = 0; i < n; i++) {
    f += a[i] - 1;
  }
  cout << f << "\n";
}
