#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int a, b, c = 0, d = 0, m, i, n, j, p, t = 0, k, array[100000 + 10],
                      ar[100000], q, sum1 = 0, cnt = 0, sum = 0, flag, ans,
                      f = 0, l;
  long long int st, ct, qt;
  string str, ptr, sp[5000];
  set<pair<long long int, long long int>> vecs;
  vector<long long int> vi(100000, 0);
  stack<long long int> stck;
  vector<char> vc;
  cin >> n >> m >> a;
  for (i = 1; i <= n; i++) {
    cin >> array[i];
  }
  sort(array, array + n + 1);
  for (i = 1; i <= n - m; i++) {
    sum = sum + array[i];
  }
  sum = sum + m * a;
  cout << sum << endl;
}
