#include <bits/stdc++.h>
using namespace std;
int unibit[60] = {0};
long long a[200005];
long long unia[200005] = {0};
int main() {
  int n, k, x;
  cin >> n >> k >> x;
  long long orr = 0;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    orr |= a[i];
    long long b = a[i];
    for (int j = 0; b > 0; j++) {
      if (b % 2 == 1) {
        if (unibit[j] == 0)
          unibit[j] = i;
        else
          unibit[j] = -1;
      }
      b /= 2;
    }
  }
  long long pow = 1;
  for (int i = 0; i < 35; i++) {
    if (unibit[i] > 0) {
      int j = unibit[i];
      unia[j] += pow;
    }
    pow *= 2;
  }
  long long ans = 0;
  long long xx = 1;
  for (int i = 0; i < k; i++) xx *= (long long)x;
  for (int i = 1; i <= n; i++) {
    long long or2 = orr;
    or2 ^= unia[i];
    a[i] *= xx;
    or2 |= a[i];
    if (ans < or2) ans = or2;
  }
  cout << ans;
  return 0;
}
