#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define pp printf("\n")
#define mo 998244353
using namespace std;
int T,n,m,ans,bz; 
int a[2048],d[2048];
vector<int>b[2048];
int dg(int x,int y,int z)
{
	if (y>z)return mo;
	if (x==0)return y;
	int l=1<<x,r=(1<<x+1)-1,zmy=mo;
	vector<int>e;
	for (int i=l/2;i<=r/2;i++)
	{
		int u=0,v=0;
		vector<int>c;
		while (u<b[i*2].size()&&v<b[i*2+1].size())if (b[i*2][u]<b[i*2+1][v])c.pb(b[i*2][u++]);else c.pb(b[i*2+1][v++]);
		while (u<b[i*2].size())c.pb(b[i*2][u++]);
		while (v<b[i*2+1].size())c.pb(b[i*2+1][v++]);
		u=0;
		for (int j=1;j<c.size();j++)if (c[j]==c[j-1]){u=1;break;}
		if (u)e.pb(i);else b[i]=c;
		//for (int j=0;j<c.size();j++)printf("%d ",c[j]);pp;
	}
	for (int i=0;i<(1<<e.size());i++)
	{
		for (int j=0;j<e.size();j++)
		if ((1<<j)&i)b[e[j]]=b[e[j]*2];else b[e[j]]=b[e[j]*2+1];
		zmy=min(zmy,dg(x-1,y+e.size(),z+1));
	}
	return zmy;
}
int main()
{
	scanf("%d",&T);
	while (T--)
	{
		scanf("%d",&m);
		n=(1<<m+1)-1; 
		for (int i=2;i<=n;i++)
		{
			scanf("%d",&a[i]);
			d[i]=d[i/2]+a[i];
		}
		for (int i=1;i<=n;i++)b[i].clear();
		for (int i=(1<<m);i<=n;i++)b[i].pb(d[i]);
		ans=dg(m,0,0);
		if (ans>m)printf("-1\n");else printf("%d\n",ans);
	}
}