#include <bits/stdc++.h>
using namespace std;
double PI = acos(-1);
int arr[10000005];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int n, m, T, res;
  int maxi = -(1 << 30) - 1, mini = (1 << 30) - 1, count = 0;
  int i, j, k;
  bool flag;
  string s1, s2;
  char s[100000];
  int ara[100005], ara2[100005];
  cin >> n;
  for (int i = (int)(0); i <= (int)(n - 1); i++) cin >> ara[i];
  for (auto x : ara) count += x;
  cout << count - n << endl;
}
