#include <bits/stdc++.h>
using namespace std;
template <class T>
inline T gcd(T a, T b) {
  if (a < 0) return gcd(-a, b);
  if (b < 0) return gcd(a, -b);
  return (b == 0) ? a : gcd(b, a % b);
}
template <class T>
inline T lcm(T a, T b) {
  if (a < 0) return lcm(-a, b);
  if (b < 0) return lcm(a, -b);
  return a * (b / gcd(a, b));
}
template <class T>
inline void checkmin(T &a, T b) {
  if (b < a) a = b;
}
template <class T>
inline void checkmax(T &a, T b) {
  if (b > a) a = b;
}
template <class T>
inline T sqr(T x) {
  return x * x;
}
template <class T>
T power(T N, T P) {
  return (P == 0) ? 1 : N * power(N, P - 1);
}
template <class T>
bool inside(T a, T b, T c) {
  return (b >= a && b <= c);
}
double dist(double x1, double y1, double x2, double y2) {
  return sqr(x1 - x2) + sqr(y1 - y2);
}
double dist(int x1, int y1, int x2, int y2) {
  return sqr(x1 - x2) + sqr(y1 - y2);
}
int toInt(string s) {
  int r = 0;
  istringstream sin(s);
  sin >> r;
  return r;
}
long long toInt64(string s) {
  long long r = 0;
  istringstream sin(s);
  sin >> r;
  return r;
}
double toDouble(string s) {
  double r = 0;
  istringstream sin(s);
  sin >> r;
  return r;
}
double LOG(long long N, long long B) { return (log10l(N)) / (log10l(B)); }
string itoa(long long a) {
  string ret;
  for (long long i = a; i > 0; i = i / 10) ret.push_back((i % 10) + 48);
  reverse(ret.begin(), ret.end());
  return ret;
}
vector<string> token(string a, string b) {
  const char *q = a.c_str();
  while (count(b.begin(), b.end(), *q)) q++;
  vector<string> oot;
  while (*q) {
    const char *e = q;
    while (*e && !count(b.begin(), b.end(), *e)) e++;
    oot.push_back(string(q, e));
    q = e;
    while (count(b.begin(), b.end(), *q)) q++;
  }
  return oot;
}
long long n, m, k;
vector<long long> V;
long long get() {
  if (n % 2 == 0) return 0;
  long long perM = m / ((n / 2) + 1);
  long long TT = perM * k;
  long long mn = 1e16;
  for (int i = 0; i < (int)V.size(); i++) {
    if (i % 2 == 0) {
      mn = min(V[i], mn);
    }
  }
  long long ret = min(TT, mn);
  return ret;
}
int main() {
  while (cin >> n >> m >> k) {
    for (__typeof(n) i = 0; i < (n); i++) {
      long long x;
      cin >> x;
      V.push_back(x);
    }
    long long ret1 = get();
    cout << ret1 << endl;
  }
}
