#include <bits/stdc++.h>
using ll = long long;
static const ll mod = 1e9 + 7;
static const ll INF = 1LL << 50;
using namespace std;
int main() {
  int n;
  vector<int> a(n);
  ll sum = 0;
  for (int i = (int)0; i < (int)n; ++i) {
    cin >> a[i];
    sum += a[i] - 1;
  }
  cout << sum << endl;
}
