#include <bits/stdc++.h>
using namespace std;
void ONLINE__JUDGE();
const int mod = 998244353;
const int MAX = 1e5 + 9;
long long x, y, z, a;
vector<long long> vec;
int main() {
  ios::sync_with_stdio(NULL);
  cin.tie(NULL);
  ONLINE__JUDGE();
  cin >> x >> y >> z;
  for (int i = 0; i < x; i++) cin >> a, vec.push_back(a);
  if (x % 2 == 0)
    cout << 0;
  else {
    long long mn = LLONG_MAX;
    for (int i = 0; i < (int)vec.size(); i += 2) mn = min(mn, vec[i]);
    long long kk = (x + 1) / 2;
    kk > y ? cout << 0 : cout << min(mn, (y / kk) * z);
  }
  return 0;
}
void ONLINE__JUDGE() {}
