#include <bits/stdc++.h>
using namespace std;
int n, m, k;
int accountes[10005];
int main() {
  scanf("%d%d%d", &n, &m, &k);
  long long Min = 1LL << 40;
  int steps = (n + 1) / 2;
  for (int i = 0; i < n; i++) {
    scanf("%d", accountes + i);
    if (!(i & 1)) Min = min((long long)accountes[i], Min);
  }
  if (n & 1) {
    if (m < steps)
      puts("0");
    else {
      long long acc = ((long long)m / steps) * k;
      cout << min(Min, acc) << endl;
    }
  } else
    puts("0");
}
