#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<functional>

#define fi first
#define se second
#define mkp std::make_pair
using ll=long long;
using llu=unsigned long long;
using std::max;
using std::min;
template<class T> void cmax(T&a,T b){a=max(a,b);}
template<class T> void cmin(T&a,T b){a=min(a,b);}

const int NV=1e5;

int QUE(int x,int y){
    printf("? %d %d\n",x,y);
    fflush(stdout);
    int t;
    scanf("%d",&t);
    return t;
}void ANSWER(int x){
    printf("! %d\n",x);
    fflush(stdout);
}

namespace xm{
    std::vector<int> G[NV+5];
    int siz[NV+5],Gc;
    bool vis[NV+5];
    void dfsgc(int x,int p,int als){
        bool F=1;
        siz[x]=1;
        for(int t:G[x]) if(t!=p&&!vis[t]){
            dfsgc(t,x,als);
            siz[x]+=siz[t];
            if(siz[t]*2>als) F=0;
        }
        if(F&&(als-siz[x])*2<=als&&!Gc) Gc=x;
    }void dfz(int x,int als){
        int chc=0,fip;
        for(int t:G[x]) if(!vis[t]){
            ++chc;
            fip=t;
        }
        vis[x]=1;
        if(chc==0){
            ANSWER(x);
            return;
        }
        if(chc==1){
            ANSWER(QUE(x,fip)==0?x:fip);
            return;
        }
        int p;
        int nsz=-1;
        std::pair<int,int> cs[3];
        chc=0;
        for(int t:G[x]) if(!vis[t])
            cs[chc++]={siz[t]>siz[x]?als-siz[x]:siz[t],t};
        std::sort(cs,cs+chc,std::greater<>());
        int t=QUE(cs[0].se,cs[1].se);
        if(t==0){
            p=cs[0].se;
        }else if(t==1){
            p=cs[2].se;
            if(!p){
                ANSWER(x);
                return;
            }
            vis[x]=0;
            vis[cs[0].se]=vis[cs[1].se]=1;
            nsz=cs[2].fi+1;
        }else if(t==2){
            p=cs[1].se;
        }
        int tsz=~nsz?nsz:(siz[p]>siz[x]?als-siz[x]:siz[p]);
        Gc=0;
        dfsgc(p,0,tsz);
        dfz(p,tsz);
    }void _(){
        int N;

        scanf("%d",&N);
        memset(vis+1,0,sizeof*vis*N);
        for(int i=1;i<=N;++i) G[i].clear();
        for(int i=1;i<=N;++i){
            int u,v;
            scanf("%d%d",&u,&v);
            if(u){
                G[i].push_back(u);
                G[u].push_back(i);
            }
            if(v){
                G[i].push_back(v);
                G[v].push_back(i);
            }
        }

        Gc=0;
        dfsgc(1,0,N);
        dfz(Gc,N);
    }
}

int main(){
    int t;
    scanf("%d",&t);
    while(t--) xm::_();
    return 0;
}