#include<bits/stdc++.h>
using namespace std;
const int M=1e5+5;
int n,fa[M],du[M];
int centroid[2];
int siz[M],weight[M];
int has[M];
struct node{
    int l,r;
}tr[M];

void getCentroid(int u){
    siz[u]=1;
    weight[u]=0;
    int l=tr[u].l,r=tr[u].r;
    if(l!=0&&!has[l])
    {
        getCentroid(l);
        siz[u]+=siz[l];
        weight[u]=max(weight[u],siz[l]);
    }
    if(r!=0&&!has[r])
    {
        getCentroid(r);
        siz[u]+=siz[r];
        weight[u]=max(weight[u],siz[r]);
    }
    weight[u]=max(weight[u],n-siz[u]);
    if(weight[u]<=n/2){
        centroid[centroid[0] != 0] = u;
    }
}
void solve(){
    cin>>n;
    for(int i=0;i<=n;i++){
        tr[i].l=tr[i].r=fa[i]=du[i]=has[i]=0;
    }
    for(int i=1;i<=n;i++){
        cin>>tr[i].l>>tr[i].r;
        fa[tr[i].l]=fa[tr[i].r]=i;
        du[tr[i].l]++; du[tr[i].r]++;
        int tmp=2;
        if(tr[i].l==0) tmp--;
        if(tr[i].r==0) tmp--;
        du[i]+=tmp;
    }
    int root;
    for(int i=1;i<=n;i++){
        if(!fa[i]){
            root=i; break;
        }
    }
    
    while(1){
        getCentroid(root);
        int cur=centroid[0];
        if(du[cur]==0){
            cout<<"! "<<cur<<endl;
            cout.flush();
            break;
        }else if(du[cur]==1){
            int u,v,tmp;
            if(tr[cur].l!=0&&!has[tr[cur].l]) v=tr[cur].l;
            else if(tr[cur].r!=0&&!has[tr[cur].r]) v=tr[cur].r;
            else v=fa[cur];
            cout<<"? "<<cur<<" "<<v<<endl;
            cin>>tmp;
            cout<<"! ";
            if(tmp==1) cout<<cur<<endl;
            else cout<<v<<endl;
            cout.flush();
            break;
        }else if(du[cur]==2){
            int u,v,tmp;
            if(tr[cur].l!=0&&!has[tr[cur].l]){
                u=tr[cur].l;
            }
            if(tr[cur].r!=0&&!has[tr[cur].r]){
                if(!u) u=tr[cur].r;
                else v=tr[cur].r;
            }
            if(fa[cur]!=0&&!has[fa[cur]]){
                if(!u) u=fa[cur];
                else v=fa[cur];
            }
            cout<<"? "<<u<<" "<<v<<endl;
            cin>>tmp;
            if(tmp==1) {
                cout<<"! "<<cur<<endl;
                cout.flush();
            }
            else if(tmp==0) {
                root=u;    n=siz[u]; du[u]--; continue;
            }
            else if(tmp==2){
                if(v==tr[cur].r){
                    root=v; n=siz[v];    du[v]--; continue;
                }else{
                    n-=siz[cur]; has[cur]++; du[fa[cur]]--; continue;
                }
                
            }
        }
        else if(du[cur]==3){
            int u,v,w,tmp;
            u=tr[cur].l,v=tr[cur].r,w=fa[cur];
            cout<<"? "<<u<<" "<<v;
            cin>>tmp;
            if(tmp==0){
                root=u;    n=siz[u]; du[u]--; continue;
            }else if(tmp==1){
                n-=siz[u];n-=siz[v];  has[u]++; has[v]++;  du[cur]-=2; continue;
            }else if(tmp==2){
                root=v;    n=siz[v]; du[v]--; continue;
            }
        }
    }
    
}

int main(){
    int t;cin>>t;
    while(t--){
        solve();
    }
}