 #include <iostream>
 using namespace std;

 int main() {
   int N; cin >> N;
   int a[i];
   int ans = 0;
   for (int i = 0; i < N; i++) {
     cin >> a[i];
     ans += a[i] - 1;
   }
   cout << ans << endl;
   return 0;
 }
