#include <bits/stdc++.h>
int main() {
  int n;
  while (scanf("%d", &n) != EOF) {
    int num[1000] = {0};
    int i = 0, t = 0, m = 0;
    while (n--) {
      scanf("%d", &num[i]);
      m += num[i];
      i++;
      t++;
    }
    int sum = 0;
    for (i = 0; i < t; i++) {
      sum += num[i];
    }
    printf("%d\n", sum - n);
  }
}
