#include <bits/stdc++.h>
using namespace std;
const int Max_N = 1e5;
bool cmp(int x, int y) { return x > y; }
void move_one(char *s, int n) {
  char t = s[0];
  for (int i = 1; i < n; ++i) s[i - 1] = s[i];
  s[n - 1] = t;
}
bool Equal(char *a, char *b) {
  int length = strlen(a);
  for (int i = 0; i < length; i++) {
    if (a[i] != b[i]) return false;
  }
  return true;
}
int main() {
  int N, a[Max_N + 5];
  int res = 0;
  for (int i = 0; i < N; ++i) {
    cin >> a[i];
    res += a[i];
  }
  cout << res - N << endl;
  return 0;
}
