#include <bits/stdc++.h>
using namespace std;
const int N = 200500;
long long a[N];
long long p[N], s[N];
int n, k, x;
long long get(int i) {
  long long res = 0;
  if (i) res |= p[i - 1];
  if (i != n - 1) res |= s[i + 1];
  return res | (a[i] * x);
}
int main() {
  cin >> n >> k >> x;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    if (i == 0)
      p[i] = a[i];
    else
      p[i] = p[i - 1] | a[i];
  }
  long long tmp = 1;
  for (int i = 0; i < k; i++) tmp *= x;
  x = tmp;
  long long res = 0;
  s[n - 1] = a[n - 1];
  for (int i = n - 2; i >= 0; i--) s[i] = s[i + 1] | a[i];
  int id = -1;
  for (int j = 0; j < n; j++)
    if (res <= get(j)) res = get(j), id = j;
  a[id] *= x;
  cout << res;
  return 0;
}
