#include <bits/stdc++.h>

using namespace std;

const int BUFFER_SIZE = 1 << 20;
char rb[BUFFER_SIZE], *rp = rb, *rt = rb;
inline char read_char() {
    return rp == rt ? (rt = rb + fread(rb, 1, BUFFER_SIZE, stdin), rp = rb, *rp ++) : *rp ++;
}
inline int read_int() {
    int x = 0;
    char ch = read_char(), flag = 0;
    while (ch != '-' && (ch < '0' || ch > '9')) {
        ch = read_char();
    }
    if (ch == '-') {
        flag = 1;
        ch = read_char();
    }
    for (x = 0; ch >= '0' && ch <= '9'; ch = read_char()) {
        x = x * 10 + (ch - '0');
    }
    return flag ? -x : x;
}

typedef long long i64;
const int MAX_N = 200000 + 5;

int N, a[MAX_N];
int al[MAX_N], ar[MAX_N];

int main() {
    N = read_int();
    int K = read_int(), X = read_int(), Y = 1;
    for (int i = 1; i <= K; i ++) Y *= X;
    for (int i = 1; i <= N; i ++) {
        a[i] = read_int();
        al[i] = al[i - 1] | a[i];
    }
    long long ans = 0;
    for (int i = N; i >= 1; i --) {
        ar[i] = ar[i - 1] | ar[i];
        ans = max(ans, al[i - 1] | ar[i + 1] | 1ll * a[i] * Y);
    }
    printf("%lld\n", ans);
    return 0;
}