#include <bits/stdc++.h>
int main(void) {
  int num;
  long *a_n, *an;
  long mod;
  scanf("%d", &num);
  a_n = (long *)malloc(sizeof(long) * num);
  int i;
  for (i = 0; i < num; i++) {
    scanf("%lld", &a_n[i]);
    mod += a_n[i] - 1;
  }
  printf("%ld", mod);
  return 0;
}
