#include <bits/stdc++.h>
using namespace std;
int a[10010];
int n, m, p;
int ans;
int main() {
  scanf("%d %d %d", &n, &m, &p);
  for (int i = 0; i < n; i++) scanf("%d", a + i);
  if (n % 2 == 1) {
    ans = 1000000001;
    for (int i = 0; i < n; i += 2) ans = min(ans, a[i]);
    int k = (n + 1) / 2;
    long long tmp = m / k;
    ans = min((long long)ans, tmp * p);
    printf("%d\n", ans);
  } else
    puts("0");
  return 0;
}
