解题思路:round()

use std::io::{self, *};
use std::str::FromStr;

fn main() {
    let stdin = io::stdin();
    unsafe {
        for line in stdin.lock().lines() {
            let ll = line.unwrap();
            println!("{}",(f64::from_str(ll.as_str()).unwrap()).round());
        }
    }
}