#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); i++)
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
using namespace std;
typedef long long ll;
int main() {
  int n; cin >> n;
  vector<int> a(n);
  rep(i, n) cin >> a[i];
  int sum=0;
  rep(i, n) 
    sum += a[i];
  ans = sum - n;
  cout << ans << endl;
}
