#include <bits/stdc++.h>
using namespace std;
long long minnn(long long x, long long y) {
  if (x < y)
    return x;
  else
    return y;
}
long long numb[200000];
int main() {
  long long n, m, k;
  int i;
  while (cin >> n >> m >> k) {
    for (i = 0; i < n; i++) cin >> numb[i];
    if (n % 2 == 0) {
      printf("0\n");
      continue;
    }
    long long op = (n + 1) / 2;
    if (op > m) {
      printf("0\n");
      continue;
    }
    long long minn = numb[0];
    for (i = 1; i * 2 < n; i++)
      if (numb[i * 2] < minn) minn = numb[i * 2];
    cout << minnn(minn, k * (m / op)) << endl;
  }
  return 0;
}
