#include <bits/stdc++.h>
using namespace std;
const int N = 251;
const int inf = 0x3f3f3f3f;
class Solution {
 public:
  int diamonds(int n, int m, int k, vector<int> a) {
    int ans = 0;
    if (n == 1) {
      ans = a[0];
      if ((long long)m * k < ans) ans = min(ans, m * k);
      return ans;
    }
    if ((n & 1) == 0) return 0;
    int d = (n + 1) >> 1;
    if (m < d) return 0;
    long long out = (long long)(m / d) * k;
    ans = a[0];
    for (int i = 0; i < n; i += 2) ans = min(ans, a[i]);
    if (out < ans) ans = out;
    return ans;
  }
};
int main() {
  int n, m, k;
  cin >> n >> m >> k;
  vector<int> a;
  for (int i = 0; i < n; i++) {
    int t;
    cin >> t;
    a.push_back(t);
  }
  Solution tester;
  cout << tester.diamonds(n, m, k, a);
  return 0;
}
