#include<bits/stdc++.h>
using namespace std;
using Int = long long;
template<typename T1,typename T2> inline void chmin(T1 &a,T2 b){if(a>b) a=b;}
template<typename T1,typename T2> inline void chmax(T1 &a,T2 b){if(a<b) a=b;}

//INSERT ABOVE HERE
signed main(){
  int n;
  cin>>n;
  using P = pair<int, int>;
  map<P, int> memo;
  int cnt=0;
  auto comp=[&](int x,int y)->bool{
              if(x==y) return false;
              if(memo.count(P(x,y))) return memo[P(x,y)];
              if(memo.count(P(y,x))) return !memo[P(y,x)];
              cnt++;
              assert(cnt<=334);
              cout<<"? "<<x<<" "<<y<<endl;
              int ans;
              cin>>ans;
              return (memo[P(x,y)]=(ans==x));
            };
  vector<int> vs(n);
  iota(vs.begin(),vs.end(),1);
  partial_sort(vs.begin(),vs.begin()+2,vs.end(),comp);
  cout<<"! "<<vs[1]<<endl;
  return 0;
}