#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=(int)a;i<(int)b;i++)
#define all(p) p.begin(),p.end()
using ll = long long;
template<class T> bool chmin(T &a, T b){return (a > b ? a = b, 1 : 0);}
template<class T> bool chmax(T &a, T b){return (a < b ? a = b, 1 : 0);}

const ll A = 3236067;
const ll B = 2000000;

void solve(){
    int N;
    cin >> N;
    auto ask = [&](int l, int r) -> int {
        cout << "? " << l + 1 << " " << r << endl;
        int res;
        cin >> res;
        return res - 1;
    };
    auto f = [&](auto self, ll l, ll r, int a = -1) -> int {
        ll len = r - l;
        if (len == 1) return l;
        if (a != -1 && len == 2){
            return (l ^ a ^ (l + 1));
        }
        if (a == -1){
            return self(self, l, r, ask(l, r));
        }
        ll diff = (len * B + A) / A;
        if (a < l + diff){
            int tmp = ask(l, l + diff);
            if (tmp == a) return self(self, l, l + diff, a);
            return self(self, l + diff, r, -1);
        }
        else{
            int tmp = ask(r - diff, r);
            if (tmp == a) return self(self, r - diff, r, a);
            return self(self, l, r - diff, -1);
        }
    };
    int ans = f(f, 0, N);
    cout << "! " << ans + 1 << endl;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int t ;
    cin >> t;
    while (t--) solve();
}