#include <bits/stdc++.h>
using namespace std;
int main(int argc, char **argv) {
  const long long nmin = 1, nmax = 10000, amin = 0, amax = 100000;
  long long n, m, mt, res, rt, i, j, k, t, ax, a;
  cin >> n >> m >> k;
  a = amax + 1;
  for (i = 0; i < n; i++) {
    cin >> rt;
    if (i % 2 == 0) a = (rt < a) ? rt : a;
  }
  res = 0;
  if ((n % 2 == 1) && (m >= (n + 1) / 2)) {
    rt = (n + 1) / 2;
    mt = m / rt;
    res = k * mt;
    res = (a < res) ? a : res;
  }
  cout << res << endl;
  return 0;
}
