#include <bits/stdc++.h>
using namespace std;

template <class A, class B> bool cmin(A& a, B b) { return a > b && (a = b, true); }
template <class A, class B> bool cmax(A& a, B b) { return a < b && (a = b, true); }

signed main() {
  cin.tie(nullptr)->sync_with_stdio(false);

  long N, X;
  cin >> N >> X;
  vector<long> A(N);
  for (long i = 0; i < N; i++) cin >> A.at(i);

  cout << accumulate(A.begin(), A.end(), 0L) - X * (N - 1) << '\n';
}