use std::io::{stdin, Read};
fn main() {
let mut buf = [0 as u8; 4096];
// println!("you need to input some thing less then 4096");
// let read_size = stdin().read(&mut buf).unwrap();
// for i in 0..read_size {
// print!("{}", buf[i] as char);
// }
println!("");
println!("i am an output!");
eprintln!("read {} size successfully", 0);
}