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

#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 mxd,dp,stk[NV+5];
    void dfs(int x,int p,int d){
        if(d>mxd){
            mxd=d;
            dp=x;
        }
        for(int t:G[x]) if(t!=p){
            dfs(t,x,d+1);
        }
    }bool dfstar(int x,int p,int tar){
        if(x==tar){
            stk[++*stk]=x;
            return 1;
        }
        for(int t:G[x]) if(t!=p)
            if(dfstar(t,x,tar)){
                stk[++*stk]=x;
                return 1;
            }
        return 0;
    }
    void _(){
        int N;

        scanf("%d",&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);
            }
        }

        int rt=1;
        for(;;){
            if(G[rt].size()==0){
                ANSWER(rt);
                return;
            }
            *stk=mxd=dp=0;
            dfs(rt,0,0);
            int u=dp,v;
            mxd=dp=0;
            dfs(u,0,0);
            v=dp;
            dfstar(u,0,v);
            std::reverse(stk+1,stk+*stk+1);
            int t=QUE(u,v);
            if(t==0){
                if(*stk==2){
                    ANSWER(u);
                    return;
                }
                int p=stk[*stk/2];
                G[p].erase(std::find(G[p].begin(),G[p].end(),
                            stk[*stk/2+1]));
                rt=p;
            }else if(t==1){
                int p=stk[*stk/2+1];
                G[p].erase(std::find(G[p].begin(),G[p].end(),
                            stk[*stk/2]));
                G[p].erase(std::find(G[p].begin(),G[p].end(),
                            stk[*stk/2+2]));
                rt=p;
            }else{
                if(*stk==2){
                    ANSWER(v);
                    return;
                }
                int p=stk[*stk-*stk/2+1];
                G[p].erase(std::find(G[p].begin(),G[p].end(),
                            stk[*stk-*stk/2]));
                rt=p;
            }
        }
    }
}

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