#include <bits/stdc++.h>
using namespace std;
int main() {
  int array[12347];
  priority_queue<int> q;
  int n, k, m, i, j, len;
  int flag = 0;
  int cou = 0;
  int max = 0;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d", array[i]);
    cou += array[i];
  }
  printf("%d", cou - n);
}
