#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, x, a, b, c = 0;
  cin >> n >> k >> x;
  int ar[n + k];
  for (a = 0; a < n + k; a++) {
    if (a < n)
      cin >> ar[a];
    else
      ar[a] = x;
  }
  sort(ar, ar + n + k);
  for (a = 0; a < n; a++) {
    c += ar[a];
  }
  cout << c;
}
