use proconio::{input, source::line::LineSource};
use std::io::{stdin, stdout, BufReader, Write};

fn main() {
    let mut source = LineSource::new(BufReader::new(stdin().lock()));

    let mut x = 1e9 as usize / 2;
    while x > 0 {
        println!("{}", x);
        stdout().flush().unwrap();

        input! {
            from &mut source,
            result: i8,
        }

        if result == 1 {
            return;
        } else if result == 0 {
            x /= 2;
        }
    }
}