#include <bits/stdc++.h>
int main() {
  int datanum;
  scanf("%d", &datanum);
  int array[100000];
  int sum;
  int i;
  for (i = 0; i < datanum; ++i) {
    scanf("%d", &array[i]);
    sum += (array[i] - 1);
  }
  printf("%d", sum);
}
