#include using namespace std; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define ll long long #define mod 1000000007 int main(){ cin.tie(0)->sync_with_stdio(0); cout.tie(0); int a,b; cout<<"? 0"<>b; cout<<"? 1"<>a; a-=b; cout<<"! "<