#include <bits/stdc++.h>
using namespace std;
const int MAX = 1e5 + 5;
const int mod = 1e9 + 7;
long long n, m, ans = 0;
int main(int argc, char** argv) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  freopen(".in", "r", stdin);
  freopen(".out", "w", stdout);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> m;
    ans += m - 1;
  }
  cout << ans;
  return 0;
}
