use chain::{
    Chain,
};
use std::{
    io::{
	BufRead,
	self,
    },
};

fn buffered_read_all_lines<T: BufRead+?Sized, F: FnMut(&str) -> io::Result<()>>(input: &mut T, mut then: F) -> io::Result<usize>
{
    let mut buffer = String::new();
    let mut read;
    let mut total=0;
    while {read = input.read_line(&mut buffer)?; read!=0} {
	then(&buffer[..])?;
	buffer.clear();
	total += read;
    }
    Ok(total)
}

fn main() {
    let stdin = io::stdin();
    let mut stdin = stdin.lock();
    let mut chain = Chain::new();

    buffered_read_all_lines(&mut stdin, |string| {
        chain.feed(&string.split_whitespace()
                   .filter(|word| !word.is_empty())
                   .map(|s| s.to_owned()).collect::<Vec<_>>());
	
	Ok(())
    }).expect("Failed to read from stdin");

    if !chain.is_empty() {
	if let Some(num) = std::env::args().skip(1).next() {
	    let sz: usize = num.parse().expect("Cannot parse number of tokens to generate");
	    for string in chain.str_iter_for(sz) {
		println!("{}", string);
	    }
	} else {
	    println!("{}", chain.generate_str());
	}
    }
}