#include <bits/stdc++.h> using namespace std; typedef signed long long ll; #undef _P #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<to;x++) #define FORR(x,arr) for(auto& x:arr) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) //------------------------------------------------------- int ask(int Y){ cout << "? " << Y << endl; int res; cin >> res; return res; } void solve() { int i,j,k,l,r,x,y; string s; x=ask(80); if(x==0) { cout << "! " << 80 << endl; return; } if(x<0) { for(i=2;i<=100;i++) { x=ask(0); if(x==0) { cout << "! " << i-1 << endl; return; } } } int L=10,R=10000000009; int num=0; while(1) { int M=(L+R)/2; x=ask(M); num++; if(x==0) { L=R=M; break; } if(x<0) { R=M; } else { L=M; R--; } } cout << "! " << L+num << endl; } int main(int argc,char** argv){ string s;int i; if(argc==1) ios::sync_with_stdio(false); FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin); solve(); return 0; }