#include <cstdio>
#include <algorithm>
using namespace std;
int n, k, x;
long long mul = 1;
long long a[200010], pre[200010], suf[200010];
int main() {
    scanf("%d%d%d", &n, &k, &x);
    for (int i = 1; i <= k; i++) {
        mul *= x;
    }
    long long ans = 0;
    for (int i = 1; i <= n; i++) {
        scanf("%lld", &a[i]);
        pre[i] = pre[i - 1] | a[i];
    }
    for (int i = n; i >= 1; i--) {
        suf[i] = suf[i + 1] | a[i];
    }
    for (int i = 1; i <= n; i++) {
        ans = max(ans, (a[i] * mul) | pre[i - 1] | suf[i + 1]);
    }
    printf("%lld\n", ans);
    return 0;
}