#include <bits/stdc++.h>
using namespace std;
int n, k, x;
long long s, t, p, ok = 0;
long long a[200001];
int b[200001][101];
int ans[101];
int main() {
  scanf("%d%d%d", &n, &k, &x);
  s = 1;
  for (int i = 1; i <= k; i++) s = s * x;
  for (int i = 1; i <= n; i++) {
    scanf("%I64d", &a[i]);
    t = a[i];
    int j = 0;
    while (t) {
      j++;
      b[i][j] = t % 2;
      ans[j] += b[i][j];
      t /= 2;
    }
  }
  int maxi = 100;
  while (maxi > 0 && ans[maxi] == 0) maxi--;
  if (maxi == 0) {
    cout << 0 << endl;
    return 0;
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= maxi; j++) ans[j] -= b[i][j];
    p = 0;
    for (int j = 1; j <= maxi; j++) {
      if (j == 1)
        t = 1;
      else
        t = t * 2;
      if (ans[j]) p = p + t;
    }
    t = p | ((long long)a[i] * s);
    if (t > ok) ok = t;
    for (int j = 1; j <= maxi; j++) ans[j] += b[i][j];
  }
  cout << ok << endl;
  return 0;
}
