#include <bits/stdc++.h>
using namespace std;
int a[10000];
int main() {
  int n, m, k, i, j;
  while (scanf("%d%d%d", &n, &m, &k) == 3) {
    for (i = 0; i < n; i++) scanf("%d", a + i);
    if (n % 2 == 0) {
      puts("0");
      continue;
    }
    int minn = 0x7fffffff;
    for (i = 0; i < n; i++) {
      if (i % 2 == 0) {
        if (a[i] < minn) {
          minn = a[i];
        }
      }
    }
    int each = (n + 1) / 2;
    long long sum = m;
    sum /= each;
    sum *= k;
    if (minn < sum) sum = minn;
    printf("%lld\n", sum);
  }
}
