#include <bits/stdc++.h>
int main() {
  long long n, m, k, min, v[10001], i, ans, p;
  scanf("%lld %lld %lld", &n, &m, &k);
  if (!(n & 1)) {
    printf("0");
    return 0;
  }
  for (i = 0; i < n; i++) scanf("%lld", &v[i]);
  min = v[0];
  for (i = 2; i < n; i += 2)
    if (v[i] < min) min = v[i];
  if (m < (n + 1) / 2) {
    printf("0");
    return 0;
  }
  p = m / ((n + 1) / 2);
  ans = (k * p < min ? k * p : min);
  printf("%lld", ans);
}
