#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)); }; const int MAX = 512; vector< vector<int> > G(MAX<<1); for(int i=0;i<n;i++) G[MAX+i].emplace_back(i+1); for(int i=MAX-1;i;i--){ int l=(i<<1)|0; int r=(i<<1)|1; if(G[l].empty()){ G[i]=G[r]; continue; } if(G[r].empty()){ G[i]=G[l]; continue; } if(!comp(G[l][0],G[r][0])) swap(l,r); G[i]=G[l]; G[i].emplace_back(G[r][0]); } int ans=*min_element(G[1].begin()+1,G[1].end(),comp); cout<<"! "<<ans<<endl; return 0; }