using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        int StaPos = 1;
        int EndPos = int.MaxValue;

        while (true) {
            int MidPos = EndPos / 2;
            if (EndPos < int.MaxValue) {
                MidPos = (StaPos + EndPos) / 2;
            }
            Console.WriteLine(MidPos);

            int GetVal = int.Parse(Console.ReadLine());
            if (GetVal == 1) {
                break;
                //StaPos = MidPos;
            }
            else {
                StaPos = MidPos;
            }
        }
    }
}