package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	n := getNextInt(scanner)
	aa := make([]float64, n)
	xx := make([]float64, n)
	var uy, ux, sigx, cov, ans float64
	for i := 0; i < n; i++ {
		aa[i] = getNextFloat64(scanner)
		xx[i] = float64(i)
		uy += aa[i]
		ux += xx[i]
	}
	uy /= float64(n)
	ux /= float64(n)
	for i := 0; i < n; i++ {
		sigx += math.Pow(xx[i]-ux, 2)
		cov += (xx[i] - ux) * (aa[i] - uy)
	}
	sigx /= float64(n)
	cov /= float64(n)
	sigx = math.Sqrt(sigx)
	a := cov / math.Pow(sigx, 2)
	b := uy - a*ux
	for i := 0; i < n; i++ {
		ans += math.Pow(float64(i)*a+b-aa[i], 2)
	}
	fmt.Fprintln(writer, fmt.Sprintf("%f %f", b, a))
	fmt.Fprintln(writer, ans)
}