#include <bits/stdc++.h>
using namespace std;
long long n, k, x, a[200005];
long long p[200005], q[200005], u[200005];
long long fac(long long a) {
  long long ans = a;
  for (int i = 0; i < k; ++i) ans *= x;
  return ans;
}
vector<long long> v;
int main() {
  cin >> n >> k >> x;
  long long maxx = -1;
  for (int i = 1; i <= n; ++i) cin >> a[i], p[i] = p[i - 1] | a[i];
  for (int i = n; i >= 1; --i) q[i] = q[i + 1] | a[i];
  for (int i = 1; i <= n; ++i) {
    long long r = 1, l = 30;
    r <<= 30;
    while (a[i] >= r) r >>= 1, --l;
    u[i] = l;
    maxx = max(maxx, l);
  }
  for (int i = 1; i <= n; ++i)
    if (u[i] == maxx) v.push_back(i);
  int len = v.size();
  maxx = -1;
  for (int i = 0; i < len; ++i) {
    maxx = max(fac(a[v[i]]) | p[v[i] - 1] | q[v[i] + 1], maxx);
  }
  cout << maxx << endl;
  return 0;
}
