#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
int main() {
  int n, sum = 0;
  cin >> n;
  int a[n];
  rep(i, n) cin >> a[i];
  sort(a, a + n);
  rep(i, n) { sum += (i + 1) - a[i]; }
  cout << sum << endl;
}