#include <iostream>
#define endl '\n'

using namespace std;

int main(void)
{
  cin.tie(NULL); ios_base::sync_with_stdio(false);
  int N; cin >> N;
  ll acc = 0;
  ll temp;
  while(N--)
  {
    cin >> temp;
    acc += temp - 1;
  }
  cout << acc << endl;
  return 0;
}