#include <bits/stdc++.h>
using namespace std;
const int MAX = 2e3 + 3;
const int INF = 1e9;
const int MOD = 1e9 + 7;
int a[MAX];
int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) cin >> a[i];
  long long ans = 0;
  for (int i = 0; i < n; i++) ans += a[i] - 1;
  cout << ans << endl;
  return 0;
}
