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

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

    let mut right = 1 << 30;
    while true {
        right = right / 2;

        println!("{}", right);
        stdout().flush().unwrap();

        input! {
            from &mut source,
            ok: usize,
        }

        if ok == 1 {
        	println!("{}", right);
        	break;
        }
    }
}