#include <bits/stdc++.h>
using namespace std;
const int oo = 1e9;
long long rooms[10001];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n, m, k;
  cin >> n >> m >> k;
  long long maxstolen = oo;
  long long ans = 0;
  for (int i = 0; i < n; i++) {
    cin >> rooms[i];
    if (i % 2 == 0) maxstolen = min(maxstolen, rooms[i]);
  }
  if (m < ceil((double)n / 2.0) || n % 2 == 0) {
    cout << ans << endl;
    return 0;
  }
  if (n == 1) {
    ans = min(m * k, rooms[0]);
  } else {
    int neededSteps = ceil((double)n / 2.0);
    int diamondsPerRun = m / neededSteps;
    ans = min(maxstolen, diamondsPerRun * k);
  }
  cout << ans << endl;
  return 0;
}
