#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define pb emplace_back
#define AI(i) begin(i), end(i)
template<class T> bool chmin(T &a, T b) { return b < a && (a = b, true); }
template<class T> bool chmax(T &a, T b) { return a < b && (a = b, true); }
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() { cerr << endl; }
template<class T, class ...U> void kout(T a, U ...b) { cerr << a << ' ', kout(b...); }
template<class T> void debug(T l, T r) { while (l != r) cerr << *l << " \n"[next(l)==r], ++l; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 17;
const ll inf = 1ll << 40;
ll pre[MAX_N][1<<MAX_N];
int n;
int a[1<<MAX_N], b[1<<MAX_N];
ll dp[2<<MAX_N];
void solve(int l, int r, int ind) {
if (l == r) return;
int mid = l + r >> 1;
solve(l, mid, ind<<1), solve(mid+1, r, ind<<1|1);
dp[ind] = dp[ind<<1] + dp[ind<<1|1];
ll inv = 0;
// cnt howmany left bigger than right;
for (int i = l, j = mid;i <= mid;++i) {
while (j < r && b[j+1] < b[i])
++j;
inv += j - mid;
}
inplace_merge(b+l, b+mid, b+r);
ll len = r - l + 1, all = (len/2) * (len/2);
dp[ind] += min(inv, all - inv);
}
ll cal() {
for (int i = 0;i < 1<<n;++i) b[i] = a[i];
solve(0, (1<<n)-1, 1);
return dp[1];
}
int tmp[1<<MAX_N];
int32_t main() {
ios_base::sync_with_stdio(0), cin.tie(0);
cin >> n;
for (int i = 0;i < 1<<n;++i)
cin >> a[i];
ll res = inf;
#define bt(v) bitset<4>(v).to_string()
for (int i = 0;i <= n;++i) {
for (int j = 0;j < 1<<n;++j) {
int nv = j >> 1 | ((j&1) << (n-1));
tmp[nv] = a[j];
}
for (int j = 0;j < 1<<n;++j)
a[j] = tmp[j];
chmin(res, cal());
}
cout << res << '\n';
}
