using System; using System.Collections.Generic; using System.Linq; class Program { static string ReadLine() { return Console.ReadLine().Trim(); } static void Main() { int x = (int)Math.Pow(10, 9); while (true) { Console.WriteLine(x); int r = int.Parse(ReadLine()); if (r == 0) x /= 2; if (r == 1) break; if (r == -1) return; } } }