#include <bits/stdc++.h>
using namespace std;
bool isPwrOf2(long long x) { return x && (!(x & (x - 1))); }
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  long long n;
  cin >> n;
  long long arr[n];
  long long cnt = 0;
  for (long long i = 0; i < n; i++) {
    cin >> arr[i];
    cnt += arr[i] - 1;
  }
  cout << cnt;
  return 0;
}
