#include <bits/stdc++.h>
using namespace std;
int n, m, k;
int arr[10005];
int main() {
  FILE *in = stdin;
  int c, c2;
  fscanf(in, "%d%d%d", &n, &m, &k);
  for (c = 0; c < n; c++) fscanf(in, "%d", &arr[c]);
  if (n % 2 == 0 || m < (n + 1) / 2)
    printf("0\n");
  else {
    int cnt = m / ((n + 1) / 2);
    int mi = 1 << 30;
    for (c = 0; c < n; c += 2) mi = min(mi, arr[c]);
    printf("%I64d\n", min((long long)mi, (long long)k * (long long)cnt));
  }
  return 0;
}
