#include <bits/stdc++.h>
using namespace std;
long long n, m, k, ans = 2001032220010322;
long long a[10004];
long long read() {
  long long f = 0;
  char ch = getchar();
  while (ch > '9' || ch < '0') ch = getchar();
  while (ch <= '9' && ch >= '0') {
    f = f * 10 + ch - '0';
    ch = getchar();
  }
  return f;
}
int main() {
  n = read();
  m = read();
  k = read();
  for (long long i = 1; i <= n; ++i) {
    a[i] = read();
  }
  if (n % 2 == 0) return puts("0");
  for (long long i = 1; i <= n; i += 2) {
    ans = min(ans, a[i]);
  }
  ans = min(ans, k * (m / ((n + 1) / 2)));
  cout << ans << endl;
  return 0;
}
