#include <bits/stdc++.h>
template <class T>
T gcd(T a, T b) {
  T r;
  while (b != 0) {
    r = a % b;
    a = b;
    b = r;
  }
  return a;
}
template <class T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
using namespace std;
const long long MOD = 1e18;
long long n, m, k, a[200005], c[1005][1005];
int main() {
  cin >> n >> m >> k;
  long long ans = MOD;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    if (i % 2) ans = min(ans, a[i]);
  }
  long long x = (m / ((n + 1) / 2)) * k;
  if (n % 2 == 0)
    cout << 0;
  else
    cout << min(ans, x);
}
