#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#define ll long long
using namespace std;
const int MN=2e5+5;
ll n,k,x,a[MN],lsum[MN],rsum[MN],ans;
void write(ll n){if(n<0){putchar('-');write(-n);return;}if(n>9)write(n/10);putchar(n%10+'0');}
ll read(){ll x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}return x*f;}
ll ksm(ll a, ll b){ll res=1;while(b){if(b&1)res*=a;a*=a;b>>=1;}return res;}
int main(){
    n=read();k=read();x=read();
    for(int i=1; i<=n; i++) a[i]=read(),lsum[i]=lsum[i-1]|a[i];
    for(int i=n; i>=1; i--) rsum[i]=rsum[i+1]|a[i];
    for(int i=1; i<=n; i++){
        ll num=a[i];num*=ksm(x,k);
        ans=max(ans,lsum[i-1]|rsum[i+1]|num);
    }
    write(ans);putchar('\n');
    return 0;
}