#include <bits/stdc++.h>
int main(int argc, char *argv[]) {
  int i, n, a[100], s = 0;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    s = s + a[i] - 1;
  }
  printf("%d\n", s);
  return 0;
}
