#include<bits/stdc++.h>

using namespace std;
const int N = 2e5 + 10;
int n , cnt , T;
int lft , rt , minn;
int head[N] , pre[N] , siz[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 getrt(int now , int fa) {
	siz[now] = 1;
	int maxsiz = 0;
	for (int i = head[now]; i; i = e[i].nxt) {
		int y = e[i].to;
		if (y == fa || del[y]) continue;
		getrt(y , now);
		maxsiz = max(maxsiz , siz[y]);
		siz[now] += siz[y];
	}
	maxsiz = max(maxsiz , lft - siz[now]);
	if (maxsiz < minn) {
		rt = now;
		minn = maxsiz;
	}
	return;
}

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

void dele(int now , int fa) {
	if (now == -1 or del[now]) return;
	del[now] = 1; --lft;
	for (int i = head[now]; i; i = e[i].nxt) {
		int y = e[i].to;
		if (y == fa) continue;
		dele(y , now);
	}
}

void solve() {
	scanf("%d" , &n);
	cnt = 0; lft = n;
	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; minn = INT_MAX;
	while (n >> lgp) {
		lgp++;
		minn = INT_MAX;
		for (int i = 1; i <= n; ++i) siz[i] = 0;
		getrt(rt , 0);
		for (int i = 1; i <= n; ++i) siz[i] = 0;
		dfs(rt , 0);
		int fir = -1 , sizfir = 0;
		int sec = -1 , sizsec = 0;
		int thir = -1;
		for (int i = head[rt]; i; i = e[i].nxt) {
			int y = e[i].to;
			if (del[y]) continue;
			if (siz[y] >= sizfir) {
				sec = fir; sizsec = sizfir;
				fir = y; sizfir = siz[y];
			}
			else if (siz[y] >= sizsec) {
				thir = sec;
				sec = y; sizsec = siz[y];
			}
			else thir = y;
		}
		if (fir == -1) {
			printf("! %d\n" , rt);
			fflush(stdout);
			return;
		}
		else {
			if (sec == -1) {
				printf("? %d %d\n" , rt , fir);
				fflush(stdout);
				int res; scanf("%d" , &res);
				if (res == 0) printf("! %d\n" , rt);
				else printf("! %d\n" , fir);
				fflush(stdout);
				return;
			}
			else {
				printf("? %d %d\n" , fir , sec);
				fflush(stdout);
				int res; scanf("%d" , &res);
				if (res == 0) {
					dele(sec , rt);
					dele(thir , rt);
					del[rt] = 1; --lft;
					rt = fir;
				}
				else if (res == 2) {
					dele(fir , rt);
					dele(thir , rt);
					del[rt] = 1; --lft;
					rt = sec;
				}
				else {
					dele(fir , rt);
					dele(sec , rt);
				}
			}
		}
	}
}

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