#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
using lP = pair<ll, ll>;
using fP = pair<double, double>;
using PPI = pair<P, int>;
ll const mod = 998244353;
const ll MAX = 200000;
using vi = vector<int>;
using vl = vector<ll>;
using vc = vector<char>;
using vd = vector<double>;
using vs = vector<string>;
using vp = vector<P>;
using vb = vector<bool>;
using vvi = vector<vector<int>>;
using vvd = vector<vector<double>>;
using vvc = vector<vector<char>>;
using vvp = vector<vector<P>>;
using vvb = vector<vector<bool>>;
template <typename T>
bool chmax(T &a, const T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T>
bool chmin(T &a, const T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
int main() {
  int n;
  int mx = 0;
  vi a(n);
  cin >> n;
  for (long long i = 0; i < n; ++i) {
    cin >> a[i];
    mx += a[i] - 1;
  }
  cout << mx << endl;
  return 0;
}
