#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define MAXN 200005
ll n,m,k,w,g[2],all=0;
string s;
vector<ll> e[MAXN];
ll sz[MAXN], weight[MAXN];
void dfs(ll u,ll fa)
{
	sz[u] = 1;
	weight[u] = 0;
	for (auto v : e[u])
	{
		if (v == fa) continue;
		dfs(v,u);
		sz[u] += sz[v];
		weight[u] = max(weight[u],sz[v]);
	}
	weight[u] = max(weight[u],all-sz[u]);
	if (weight[u] <= all / 2)
	{
		g[g[0] != 0] = u;
	}
}
ll siz[MAXN];
void dfs_2(int u,int fa)
{
	siz[u] = 1;
	for (auto v : e[u])
	{
		if (v == fa) continue;
		dfs_2(v, u);
		siz[u] += siz[v];
	}
}
int ask(int a,int b)
{
	int x;
	cout << "? " << a << ' ' << b << endl;
	cin >> x;
	return x;
}
void solve()
{
	cin >> n;
	for (int i = 1; i <= n; i++) e[i].clear();
	for (int i = 1; i <= n; i++)
	{
		int u, v;
		cin >> u >> v;
		if (u != 0) e[u].push_back(i), e[i].push_back(u);
		if (v != 0) e[v].push_back(i), e[i].push_back(v);
	}
	g[0] = 0, g[1] = 0;
	dfs_2(1, 0);
	all = siz[1];
	dfs(1,0);
	while (e[g[0]].size()!=0)
	{
		if (e[g[0]].size() == 0)
		{
			break;
		}
		else if (e[g[0]].size() == 1)
		{
			int tag=ask(e[g[0]][0],g[0]);
			if (tag == 0)
			{
				swap(e[g[0]][0],g[0]);
			}
			break;
		}
		else if(e[g[0]].size()==2)
		{
			int tag=ask(e[g[0]][0],e[g[0]][1]);
			if (tag == 0)
			{
				int cnt = 0;
				for (auto i : e[e[g[0]][0]])
				{
					if (i == g[0]) break;
					cnt++;
				}
				e[e[g[0]][0]].erase(e[e[g[0]][0]].begin()+cnt);
				int now = e[g[0]][0];
				g[0] = 0, g[1] = 0;
				dfs_2(now, 0);
				all = siz[now];
				dfs(now, 0);
			}
			else if(tag==1)
			{
				break;
			}
			else
			{
				int cnt = 0;
				for (auto i : e[e[g[0]][1]])
				{
					if (i == g[0]) break;
					cnt++;
				}
				e[e[g[0]][1]].erase(e[e[g[0]][1]].begin() + cnt);
				int now = e[g[0]][1];
				g[0] = 0, g[1] = 0;
				dfs_2(now, 0);
				all = siz[now];
				dfs(now, 0);
			}
		}
		else
		{
			dfs_2(g[0], 0);
			sort(e[g[0]].begin(), e[g[0]].end(), [&](int x, int y)
			{
				return siz[x] > siz[y];
			});
			int tag=ask(e[g[0]][0],e[g[0]][1]);
			if (tag == 0)
			{	
				int cnt = 0;
				for (auto i : e[e[g[0]][0]])
				{
					if (i == g[0]) break;
					cnt++;
				}
				e[e[g[0]][0]].erase(e[e[g[0]][0]].begin() + cnt);
				int now = e[g[0]][0];
				g[0] = 0, g[1] = 0;
				dfs_2(now, 0);
				all = siz[now];
				dfs(now, 0);
			}
			else if(tag==1)
			{	
				
				e[g[0]].erase(e[g[0]].begin());
				e[g[0]].erase(e[g[0]].begin());
				int now = e[g[0]][0];
				g[0] = 0, g[1] = 0;
				dfs_2(now, 0);
				all = siz[now];
				dfs(now, 0);
				//cout << e[now].size() << endl;
			}
			else
			{
				int cnt = 0;
				for (auto i : e[e[g[0]][2]])
				{
					if (i == g[0]) break;
					cnt++;
				}
				e[e[g[0]][2]].erase(e[e[g[0]][2]].begin() + cnt);
				int now = e[g[0]][2];
				g[0] = 0, g[1] = 0;
				dfs_2(now, 0);
				all = siz[now];
				dfs(now, 0);
			}
		}
	}
	cout << "! " << g[0] << endl;
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int T = 1;
	cin >> T;
	while (T--)
	{
		solve();
	}
}