#include <bits/stdc++.h>
using namespace std;

#define int long long

const int N = 5005, NN = 2e5 + 5;

int n,K,x,a[N],g[N][N];

int f[N][20];

int pre[NN], suf[NN];

int b[NN];

signed main(){
    cin >> n >> K >> x;
    if (n > 5000){
        for (int i = 1;i <= n;i++)
            cin >> b[i];
        if (K == 1){
            for (int i = 1;i <= n;i++)
                pre[i] = pre[i - 1] | b[i];
            for (int i = n;i >= 1;i--)
                suf[i] = suf[i + 1] | b[i];
            int ans = 0;
            for (int i = 1;i <= n;i++){
                ans = max(ans,pre[i - 1] | suf[i + 1] | (b[i] * x));
            }
            cout << ans;
        }
        else{
            sort(b + 1,b + n + 1,[](int x,int y){
                return y > x;
            });
            for (int i = 1;i <= K;i++){
                b[i] *= x;
            }
            int ans = 0;
            for (int i = 1;i <= n;i++)
                ans |= b[i];
            cout << ans;
        }
        return 0;
    }
    for (int i = 1;i <= n;i++){
        cin >> a[i];
    }
    for (int i = 1;i <= n;i++){
        g[i][i] = a[i];
        for (int j = i + 1;j <= n;j++){
            g[i][j] = g[i][j - 1] | a[j];
        }
    }
    for (int i = 1;i <= n;i++){
        for (int j = 0;j < i;j++){
            for (int k = 0;k <= min(K,i);k++){
                if (k)
                    f[i][k] = max(f[i][k],f[j][k - 1] | g[j + 1][i - 1] | (a[i] * x));
                f[i][k] = max(f[i][k],f[j][k] | g[j + 1][i]);
            }
        }
    }
    int ans = 0;
    for (int i = 1;i <= K;i++)
        ans = max(ans,f[n][i]);
    cout << ans;
    return 0;
}