#define rep(i, n) for (int i = 0; i < (int)(n); i++) #define ALL(v) v.begin(), v.end() typedef long long ll; #include using namespace std; int main(){ int l=0,r=1e9+1; while(r-l>1){ int m=(r+l)/2; cout<<"? "<>x; if(x==1) r=m; else l=m; } cout<<"! "<