#include<bits/stdc++.h>
using namespace std;
#define int long long
#define PII pair<int,int>
#define lson 2*p
#define rson 2*p+1
#define x first
#define y second
// #define endl "\n"
const int N=2e5+10;
const int mod=1e9+7;
vector<int> v;
int last=-1;
int ans=0;
int ask(int l,int r) {
	cout<<"? "<<l<<" "<<r<<endl;
	int k;
	cin>>k;
	return k;
}
void solve(int l,int r) {
	if(ans) return ;
//	if(l>=r) return ;
	if(l==r) {
		ans=l;
		return ;
	}
	if(l==r-1) {
		ans=(l^r^ask(l,r));
		return ;
	}
	int res=(r-l+1)/3;
	if(last!=-1) {
		int p=ask(l,l+res-1);
		if(last==p) solve(l,l+res);
		else solve(l+res,r),last=-1;
	} else {
		int k=ask(l,r);
		int p=ask(l,l+res);
		if(k==p) solve(l,l+res),last=p;
		else solve(l+res+1,r);
	}
}
void solve() {
	int n;
	cin>>n;
	solve(1,n);
	cout<<"! "<<ans<<endl;
} 
signed main() {
//	ios::sync_with_stdio(false);
//	cin.tie(0);
	int T=1;
	 cin>>T;
	while(T--) {
		solve();
	}
}