#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T sqr(T x) {
  return x * x;
}
long long n, m, k;
long long v[10006];
int main() {
  while (scanf("%lld%lld%lld", &n, &m, &k) != EOF) {
    int i;
    for (i = 0; i < n; i++) {
      scanf("%lld", &v[i]);
    }
    if (n % 2 == 0) {
      printf("0\n");
      continue;
    }
    long long minl = 10000000;
    long long mm = (n + 1) / 2;
    if (m < mm) {
      printf("0\n");
      continue;
    }
    for (i = 0; i < n; i += 2) {
      minl = (((minl) < (v[i])) ? (minl) : (v[i]));
    }
    printf("%lld\n", (((minl) < (k * (m / mm))) ? (minl) : (k * (m / mm))));
  }
  return 0;
}
