#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, n;
  long long k, time, maks, tot, ar[10005], ans, temp, m;
  bool cek;
  scanf("%d %I64d %I64d", &n, &m, &k);
  for (i = 0; i < n; ++i) scanf("%I64d", &ar[i]);
  if ((n % 2) == 0)
    printf("0\n");
  else {
    ans = 0;
    time = (n + 1) / 2;
    if (time > m)
      printf("0\n");
    else {
      temp = m / time;
      maks = temp * k;
      ans = ar[0];
      for (i = 2; i < n; i += 2) ans = min(ans, ar[i]);
      ans = min(ans, maks);
      printf("%I64d\n", ans);
    }
  }
  return 0;
}
