#include <bits/stdc++.h>
int a[3005];
int main() {
  int n;
  long long sum = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  for (int i = 0; i < n; i++) sum += a[i] - 1;
  printf("%lld", sum);
  return 0;
}
