#![allow(non_snake_case)]

use std::io::{ self, prelude::* };

macro_rules! pick {
    ($tokens:expr) => {
        $tokens.next().unwrap().parse().expect("parse error")
    }
}

fn main() {
    let mut s = String::new();
    io::stdin().read_to_string(&mut s).expect("i/o error");
    let mut tokens = s.split_whitespace();

    let N: usize = pick!(tokens);
    let mut A = Vec::<(f64,f64)>::with_capacity(N);
    for i in 0..N {
        let y = pick!(tokens);
        A.push((i as f64,y))
    }
    let N = N as f64;

    let mean_x = A.iter()
        .map(|&(x,_)| x)
        .sum::<f64>() / N;
    let mean_y = A.iter()
        .map(|&(_,y)| y)
        .sum::<f64>() / N;
    let var_x = A.iter()
        .map(|&(x,_)| x)
        .fold(0.0, |sum,x| sum + (x-mean_x).powf(2.0)) / N;
    let cov_xy = A.iter()
        .fold(0.0, |sum,(x,y)| sum + x*y) / N - mean_x*mean_y;

    let d = cov_xy / var_x;
    let b = mean_y - d*mean_x;
    let c = A.iter()
        .fold(0.0, |sum,(x,y)| sum + (b+d*x - y).abs().powf(2.0));

    println!("{} {}", b, d);
    println!("{}", c);
}