#include <bits/stdc++.h>
using namespace std;
int N;
long long M, K;
int A[10500];
int main() {
  scanf("%d%lld%lld", &N, &M, &K);
  if (N % 2 == 0) return 0 & puts("0");
  for (int i = 1; i <= N; i++) scanf("%d", A + i);
  int c = (N + 1) / 2;
  int m = (int)1e6;
  for (int i = 1; i <= N; i += 2) {
    m = min(m, A[i]);
  }
  printf("%lld\n", min(K * (M / c), (long long)m));
  return 0;
}
