This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define db double
#define pairll pair<ll,ll>
#define lpairll pair<ll,pairll>
#define repp(i,a,b) for (ll i = a; i <= b; i++)
#define repz(i,a,b) for (ll i = a; i < b; i++)
#define repm(i,a,b) for (ll i = a; i >= b; i--)
#define fr first
#define sc second
#define mp make_pair
#define pb push_back
const ll N = 1e5+5, MOD = 1e9+7;
ll tc = 1, n, m, fnd[N];
ll x, y, k;
string s, s1, s2, ye = "YES", no = "NO";
char cr[N];
ll ask(ll l, ll r){
  cout << "? " << l << " " << r << endl;
  cin >> m; return m;
}
int main(){
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> n >> k;
  vector<ll> ntbgt;
  ntbgt.pb(1);
  cr[1] = '(';
  repp(i,2,n){
    ll a1;
    if (ntbgt.size() && ask(ntbgt.back(),i)){
      cr[i] = ')';
      ntbgt.pop_back();
    }
    else{
      cr[i] = '(';
      ntbgt.pb(i);
    }
  }
  ll sz = ntbgt.size()/2;
  repz(i,0,sz){
    cr[ntbgt[i]] = ')';
  }
  cout << "! ";
  for (ll i = 1; i <= n; i++){
    cout << cr[i];
  }
  cout << endl;
}
Compilation message (stderr)
zagrade.cpp: In function 'int main()':
zagrade.cpp:37:8: warning: unused variable 'a1' [-Wunused-variable]
   37 |     ll a1;
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