#include <bits/stdc++.h>
using namespace std;
long long a[100000] = {0};
int main() {
  for (long long n, m, k; cin >> n >> m >> k;) {
    long long i;
    for (i = 0; i < n && cin >> a[i]; i++)
      ;
    long long t = m / ((n + 1) / 2);
    if (n % 2 == 0) {
      cout << 0 << endl;
      continue;
    }
    if (t == 0) {
      cout << 0 << endl;
      continue;
    }
    long long tt = a[0];
    for (i = 2; i < n; i += 2) {
      if (a[i] < tt) tt = a[i];
    }
    cout << (k * t > tt ? tt : k * t) << endl;
  }
}
