#include <bits/stdc++.h>
using namespace std;
long long a[100005], b[15][15], cnt[100005];
vector<long long> g[15];
long long n, m, X, Y, ans = 0;
void input() {
  cin >> n;
  for (long long i = 1; i <= n; ++i) {
    cin >> a[i];
    ans += a[i] - 1;
  }
  cout << ans;
  return;
}
void solve() { return; }
void output() { return; }
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  {
    input();
    solve();
    output();
  }
  return 0;
}
