#include<iostream>
#include<algorithm>
using namespace std;

#define NUM 100000

int main(){
  int n;
  cin >> n;
  int m = 0;
  int a[NUM];
  for (int i=0; i<n; i++){
    cin >> a[i];
    m += a[i];
  }
  cout << m-n << end;
}