#include <bits/stdc++.h>
using namespace std;
long long int N, S[100005];
long long int ans, M, K;
int main() {
  scanf("%lld%lld%lld", &N, &M, &K);
  for (long long int i = 1; i <= N; ++i) scanf("%lld", &S[i]);
  if ((N & 1ll) == 0)
    printf("0\n");
  else if (N == 1)
    printf("%lld\n", min(M * K, S[1]));
  else {
    ans = S[1];
    for (long long int i = 1; i <= N; i += 2) ans = min(ans, S[i]);
    ans = min((M * 2ll / (N + 1ll)) * K, ans);
    printf("%lld\n", ans);
  }
}
