#include<bits/stdc++.h>

using namespace std;
const int N = 2e5 + 10;
int n, cnt, T;

int head[N], dep[N], pre[N];
bool del[N];

struct Edge{
    int to, nxt;
}e[N << 1];

void add(int u, int v) {
    e[++cnt].to = v;
    e[cnt].nxt = head[u];
    head[u] = cnt;
}

void get_root(int now, int fa) {
    if(now == -1) return;
    for(int i = head[now]; i; i = e[i].nxt) {
        int y = e[i].to;
        if(y == fa || del[y]) continue;
        dep[y] = dep[now] + 1;
        get_root(y, now);
    }
}

void get_d(int now, int fa) {
    if(now == -1) return;
    for(int i = head[now]; i; i = e[i].nxt) {
        int y = e[i].to;
        if(y == fa || del[y]) continue;
        dep[y] = dep[now] + 1;
        pre[y] = now;
        get_d(y, now); 
    }
}

void solve() {
    scanf("%d", &n);
    cnt = 0;
    for(int i = 1; i <= n; ++i) head[i] = del[i] = 0;
    for(int i = 1; i <= n; ++i) {
        int lson, rson;
        scanf("%d%d", &lson, &rson);
        if(lson) {
            add(i, lson); add(lson, i);
        }
        if(rson) {
            add(i, rson); add(rson, i);
        }
    }
    
    int lgp = 0, rt = 1;
    while(1) {
        //printf("%d:\n", lgp);
        lgp++;

        for(int i = 1; i <= n; ++i) {
            dep[i] = pre[i] = 0;
        }
        get_root(rt, 0);
        int S = -1, maxn = 0, T = -1;
        for(int i = 1; i <= n; ++i) {
            if(dep[i] > maxn) {
                maxn = dep[i];
                S = i;
            }
        }
        if(S == -1) {
            printf("! %d\n",rt);
             fflush(stdout); 
            //break;
            return;
        }
        for(int i = 1; i <= n; ++i) dep[i] = 0;
        get_d(S, 0); 
        maxn = 0;
        for(int i = 1; i <= n; ++i) {
            if(dep[i] > maxn) {
                maxn = dep[i];
                T = i;
            }
        }
        if(T == -1) {
            printf("! %d\n", S);
            fflush(stdout); 
            return;
        }
        printf("? %d %d\n", T, S);
        fflush(stdout); 
        vector<int>v;
        while(T != S) {
            v.push_back(T);
            T = pre[T];
        }
        v.push_back(S);
        // for(int i = 0; i < v.size(); ++i) {
        //     printf("%d ", v[i]);
        // }puts("");

        int res;
        scanf("%d", &res);
        if(res == 0) {
            int mid = v.size() / 2;
            int i = v.size() - 1, j = 0;
            for(i = v.size() - 1, j = 1; j <= mid; --i, ++j) {
                del[v[i]] = 1;
               // printf("del:%d\n", v[i]);
            }
            rt = v[i]; 
        }
        else if(res == 2) {
            int mid = v.size() / 2;
            int i = 0, j = 0;
            for(i = 0, j = 1; j <= mid; ++i, ++j) {
                del[v[i]] = 1;
            }
            rt = v[i];
        }
        else {
            rt = v[v.size() / 2];
            for(int i = 0; i < v.size(); ++i) {
                if(v[i] != rt) del[v[i]] = 1;
            }
        }
        //printf("rt: %d\n", rt);
    }
}

signed main() {
    scanf("%d", &T);
    while(T--) solve();
}