#include <bits/stdc++.h>
int main() {
  int n, num, ans;
  while (~scanf("%d", &n)) {
    ans = 0;
    for (int i = 0; i < n; i++) {
      scanf("%d", &num);
      ans += num - 1;
    }
    printf("%d\n", ans);
  }
  return 0;
}
