#include <bits/stdc++.h>
#define lli long long
#define plli pair<lli, lli>
#define MAX 200005
const int MOD = 1000000007;

using namespace std;

vector<int> adj[MAX];
vector<bool> is_removed(MAX);
vector<int> subtree_size(MAX);
int ans;

/** DFS to calculate the size of the subtree rooted at `node` */
int get_subtree_size(int node, int parent = -1) {
	subtree_size[node] = 1;
	for (int child : adj[node]) {
		if (child == parent || is_removed[child]) { continue; }
		subtree_size[node] += get_subtree_size(child, node);
	}
	return subtree_size[node];
}

/**
 * Returns a centroid (a tree may have two centroids) of the subtree
 * containing node `node` after node removals
 * @param node current node
 * @param tree_size size of current subtree after node removals
 * @param parent parent of u
 * @return first centroid found
 */

int query(int fir,int sec){
    cout<<"? "<<fir<<" "<<sec<<"\n";
    cout.flush();
    int val;
    cin>>val;
    return val;
}
int get_centroid(int node, int tree_size, int parent = -1) {
    vector<pair<int,int>> szchild;
    int sztot=0;
	for (int child : adj[node]) {
		if(is_removed[child]){ 
            continue; 
        }

        if (child == parent){
            continue;
        }

		if (subtree_size[child] * 2 > tree_size) {
			return get_centroid(child, tree_size, node);
		}
        sztot+=subtree_size[child];
        szchild.push_back({subtree_size[child],child});
	}
    // we got the centroid . now query
    if(parent!=-1 && !is_removed[parent]){
        szchild.push_back({tree_size-sztot,parent});
    }
    if(szchild.size()==0){
        ans=node;
        // cout<<"here 0\n";
    }else if(szchild.size()==1){

        int who=query(node,szchild[0].second);
        if(who==0){
            ans=node;
            is_removed[szchild[0].second]=true;
        }else{
            is_removed[node]=true;
            ans=szchild[0].second;
        }
        
        // cout<<"here 1\n";
    }else if(szchild.size()==3){
        // cout<<"here 3\n";
        sort(szchild.begin(),szchild.end());
        int who=query(szchild[1].second,szchild[2].second);
        if(who==1){
            is_removed[szchild[1].second]=true;
            is_removed[szchild[2].second]=true;
        }else if(who==0){
            is_removed[node]=true;
            is_removed[szchild[2].second]=true;
            is_removed[szchild[0].second]=true;
        }else{
            is_removed[node]=true;
            is_removed[szchild[1].second]=true;
            is_removed[szchild[0].second]=true;
        }
    }else if(szchild.size()==2){
        // cout<<"here 2\n";
        int who=query(szchild[0].second,szchild[1].second);
        if(who==1){
            is_removed[szchild[1].second]=true;
            is_removed[szchild[0].second]=true;
            ans=node;
        }else if(who==0){
            is_removed[node]=true;
            is_removed[szchild[1].second]=true;
        }else{
            is_removed[node]=true;
            is_removed[szchild[0].second]=true;
        }
    }
	return node;
}

/** Build up the centroid decomposition recursively */
void build_centroid_decomp(int node = 0) {
	int centroid = get_centroid(node, get_subtree_size(node));

	// do something

	// is_removed[centroid] = true;

	for (int child : adj[centroid]) {
		if (is_removed[child]) { continue; }

		build_centroid_decomp(child);
        if(ans!=-1){
            break;
        }
	}
}


int main(){
    // ios::sync_with_stdio(0);
    // cin.tie(0);cout.tie(0);

    int t=1;
    cin>>t;

    while(t--){

        int n;
        cin>>n;

        for(int i=0;i<=n;i++){
            adj[i].clear();
            is_removed[i]=0;
            subtree_size[i]=0;
        }
        ans=-1;

        for(int i=1;i<=n;i++){
            int l,r;
            cin>>l>>r;

            if(l!=0){
                adj[i].push_back(l);
                adj[l].push_back(i);
            }
            if(r!=0){
                adj[i].push_back(r);
                adj[r].push_back(i);
            }
        }

        build_centroid_decomp(1);

        cout<<"! "<<ans<<"\n";
        cout.flush();
    }
}