import sequtils,math

proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "<stdio.h>" .}
proc scan(): int =
  while true:
    let k = getchar_unlocked()
    if k < '0': break
    result = 10 * result + k.ord - '0'.ord

let n = scan()
let A = newSeqWith(n,scan().float)
proc calcCost(b,d:float):float =
  for i,a in A:
    let bi = b + d * i.float
    result += (a - bi)*(a - bi)
let S = toSeq(0..<n)
let d1 = n.float * S.mapIt(it.float * A[it]).sum()
let d2 = S.sum().float * A.sum()
let d3 = n.float * S.mapIt(it * it).sum().float
let d4 = S.sum().float * S.sum().float
let d = (d1 - d2) / (d3 - d4)
let b1 = S.mapIt(it * it).sum().float * A.sum()
let b2 = S.mapIt(it.float * A[it]).sum() * S.sum().float
let b = (b1 - b2) / (d3 - d4)
echo b," ",d
echo calcCost(b,d)