#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
const long long INF = 1LL << 60;
const ll C = 1000000000 + 7;
int main(void) {
  int N, ans;
  cin >> N;
  vector<int> a(N);
  for (int i = 0; i < N; i++) {
    cin >> a[i];
    ans += a[i] - 1;
  }
  cout << ans << endl;
}
