#include <bits/stdc++.h>
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 10086;
long long f[MAXN];
int main() {
  long long i, j, k;
  long long m, n;
  long long tc, c, mm;
  scanf("%lld %lld %lld", &n, &m, &k);
  for (i = 0; i < n; ++i) {
    scanf("%lld", f + i);
  }
  if (n % 2 == 0) {
    printf("0\n");
  } else {
    c = m / ((n + 1) >> 1);
    mm = INF;
    for (i = 0; i < n; ++i, ++i) mm = min(mm, f[i]);
    printf("%lld\n", min(mm, c * k));
  }
  return 0;
}
