#include <bits/stdc++.h>
using namespace std;
long long n, n1, k, x, i = 0, m, su = 0, su1, su2, I, maximo = 0;
vector<int> a, b, c;
int main() {
  cin >> n >> k >> x;
  i = 0;
  while (i < n) {
    cin >> m;
    a.push_back(m);
    i++;
  }
  i = 0;
  n1 = n - 1;
  b.push_back(a[0]);
  c.push_back(a[n1]);
  while (i < (n - 2)) {
    b.push_back(b[i] | a[i + 1]);
    c.push_back(c[i] | a[n1 - i - 1]);
    i++;
  }
  i = 0;
  n1 = n - 1;
  while (i < n) {
    su = 0;
    su1 = 0;
    su2 = a[i] * pow(x, k);
    if (i != 0) su = b[i - 1];
    if (i != n1) su1 = c[n1 - i - 1];
    maximo = max(maximo, (su | su1 | su2));
    i++;
  }
  cout << maximo;
  return 0;
}
