#include <bits/stdc++.h>
using namespace std;
const int maxn = 100010;
int a[maxn];
int main() {
  int n;
  long long s = 0;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (int j = 0; j < n; j++) s += a[j] - 1;
  cout << s;
  return 0;
}
