#include <bits/stdc++.h>
using namespace std;
template <typename T>
class List : public vector<T> {
 public:
  template <typename... U>
  List(const U &...tail) : vector<T>(0) {
    pb(tail...);
  }
  void pb() {}
  template <typename... U>
  void pb(const T &head, const U &...tail) {
    this->emplace_back(head);
    pb(tail...);
  }
  void print() {
    const int LEN = this->size();
    for (int i = 0; i < LEN; i++) {
      cout << (*this)[i] << (i == LEN - 1 ? '\n' : ' ');
    }
  }
};
pair<long long, long long> exgcd(const long long x, const long long y) {
  if (!y) {
    return make_pair(1, 0);
  }
  pair<long long, long long> cur = exgcd(y, x % y);
  return make_pair(cur.second, cur.first - (x / y) * cur.second);
}
const long long __mod__ = 998244353;
long long mmod() { return 1LL; }
template <typename T, typename... U>
long long mmod(const T &head, const U &...tail) {
  return (head * mmod(tail...)) % __mod__;
}
long long mod(long long x, long long p = __mod__) { return ((x % p) + p) % p; }
void print() {}
template <typename T, typename... U>
void print(const T &head, const U &...tail) {
  cout << head << (sizeof...(tail) ? ' ' : '\n');
  print(tail...);
}
inline long long fmul(long long a, long long c, const long long &Mod) {
  a %= Mod, c %= Mod;
  return (a * c - (long long)(((long double)a * c + 0.5) / Mod) * Mod) % Mod;
}
long long gcd(long long x, long long y) { return y == 0 ? x : gcd(y, x % y); }
void solve();
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}
long long a[3333];
void solve() {
  int n;
  cin >> n;
  int sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  cout << (sum - n) << "\n";
}
