package yukicoder253;
import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		System.out.println("?100	");
		int a=sc.nextInt();
		int count=0;
		if(a==-1){
			for(int i=0;i<100;i++){
				System.out.println("?0");
				count++;
				int b=sc.nextInt();
				if(b==0){
					System.out.println("!"+count);
					sc.close();
					System.exit(0);
				}
			}
		}else{
			if(a==1){
				int upper=(int)Math.pow(10,9);
				int low=100;
				int mid=(int)(upper+low)/2;
				
				while(low!=upper){
					count++;
					System.out.println("?"+mid);
					int r=sc.nextInt();
					if(r==1){
						mid=(upper+mid)/2;
					}else if(r==-1){
						mid=(low+mid)/2;
					}else if(r==1){
						System.out.println("!"+(mid+count));
						sc.close();
						System.exit(0);
					}
				}
			}else if(a==0){
				System.out.println("!100");
				sc.close();
				System.exit(0);
			}
			
		}
	}
}