#include <bits/stdc++.h>
using namespace std;
inline int nextInt() {
  int val = 0, ope = 1, ch;
  while (ch = getchar(), ch == ' ' || ch == '\n')
    ;
  if (ch == EOF) exit(0);
  if (ch == '-')
    ope = 0;
  else
    val = ch - '0';
  while (ch = getchar(), ch != ' ' && ch != '\n') val = val * 10 + ch - '0';
  return ope ? val : -val;
}
const int MAXN = 10086;
int ar[MAXN], sum[MAXN];
int br[MAXN];
int main() {
  int n, m, k;
  while (EOF != scanf("%d%d%d", &n, &m, &k)) {
    for (int i = 1; i <= n; ++i) {
      scanf("%d", &ar[i]);
    }
    if (n % 2 == 0) {
      puts("0");
      continue;
    }
    int ret = INT_MAX;
    for (int i = 1; i <= n; i += 2) {
      ret = min(ret, ar[i]);
    }
    long long ans = ((long long)m / ((n / 2) + 1)) * (long long)k;
    printf("%lld\n", min(ans, (long long)ret));
  }
  return 0;
}
