#include<bits/stdc++.h>
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define int long long
int cnt = 0;
int len = 0;
int C = 0;
int L = 0;
int ask(int l , int r){
    if(l == r) return -1;
    cnt++;
    len += r - l + 1;
    assert(cnt <= C);
    assert(len <= L);
    cout <<"? " <<l <<' '<<r <<endl;
    int ret;
    cin >> ret;
    return ret;
}

void answer(int x){
    cout <<"! " << x <<endl;
}
void f(int l , int r);
void g(int l ,int r ,int x);
const double a=pow(2,2.0/3.0);
const double dx = 0.618;
void solve() {
     int n;
     cin >> n;
     L = 3 * n;
     C = ceil(1.5 * log2(n));
     cnt = len = 0;
     f(1 , n);
}

int32_t main(){
    fastio;
    int tc;cin>>tc;
    while(tc--)solve();
    return 0;
}


void f(int l,int r){
    assert(l <= r);
    if(l >= r){
        answer(l);
        return;
    }
    int s = ask(l , r);
    g( l , r, s);
}

void g(int l , int r , int x){
    int len = ceil((r - l + 1) * dx - 1);
    assert(l != r);
    if(r - l + 1 <= 2){
        answer(l ^ r ^ x);
        return;
    }
    if(l + len >= x){
        int R = l + len;
        int s = ask(l , R);
        if(s != x) f(R + 1, r);
        else g(l , R , x);
    }
    else{
        int L = r - len;
        int s = ask(L , r);
         if(s != x) f(l, L - 1);
        else g(L, r , x);
    }
}