#include <bits/stdc++.h>
using namespace std;
int num[10006];
int main() {
  int n, m, k;
  scanf("%d %d %d", &n, &m, &k);
  for (int i = 1; i <= n; ++i) scanf("%d", num + i);
  if (n & 1) {
    long long minn = 0x3fffffff;
    for (int i = 1; i <= n; i += 2) minn = min(minn, (long long)num[i]);
    long long ans = (long long)k * ((long long)m / ((n + 1) / 2));
    ans = min(ans, minn);
    printf("%d\n", (int)ans);
  } else {
    printf("%d\n", 0);
  }
  return 0;
}
