#include <bits/stdc++.h>
using namespace std;
inline int SG(double x) { return x > -1E-8 ? x < 1E-8 ? 0 : 1 : -1; }
int c[1000000];
int main() {
  int n, m, r, i, j, k, d;
  long long md;
  scanf("%d %d %d", &n, &m, &r);
  for (i = 0; i < (n); i++) {
    scanf("%d", &c[i]);
  }
  if (n % 2 == 0) {
    puts("0");
    return 0;
  }
  d = (n + 1) / 2;
  md = (long long)(m / d) * (long long)r;
  for (i = 0; i < n; i += 2) {
    if (c[i] < md) md = c[i];
  }
  printf("%I64d\n", md);
  return 0;
}
