import java.util.Scanner; public class Yukicoder246 { public static void main(String[] args) { int min = 0, max = 1000000000, mid; Scanner sc = new Scanner(System.in); while (Math.abs(max-min) > 1) { mid = (max + min) / 2; System.out.println("?" + mid); if (sc.nextInt() == 1) min = mid; else max = mid; } System.out.println("!" + min); } }