#include<iostream>

#include<cstring>

#include<cstdlib>

#include<cstdio>

#include<algorithm>

#define ll long long

using namespace std;

const int maxn=;

ll n, k, x;

ll a[maxn], b[maxn], qzh[maxn], hzh[maxn], ans;

void read(ll &k)

{

    int f=; k=; char c=getchar();

    while(c<'' || c>'') c=='-' && (f=-), c=getchar();

    while(c<='' && c>='') k=k*+c-'', c=getchar();

    k*=f;

}

int main()

{

    read(n); read(k); read(x);

    for(int i=;i<=n;i++)

    {

        read(a[i]); b[i]=a[i];

        for(int j=;j<=k;j++) b[i]*=x;

        qzh[i]=qzh[i-]|a[i];

    }

    for(int i=n;i;i--) hzh[i]=hzh[i+]|a[i];

    for(int i=;i<=n;i++) ans=max(ans, qzh[i-]|b[i]|hzh[i+]);

    printf("%I64d\n", ans);

}