n = io.read("*n")
t = {}
k1, k2, k3, k4 = 0, 0, 0, 0
for i = 0, n - 1 do
    v = io.read("*n")
    table.insert(t, v)
    k1 = k1 - i
    k2 = k2 + i * i
    k3 = k3 + i * v
    k4 = k4 + v
end
-- a = (k1 / k2) * b + (k3 / k2)
-- b = (k1 / n) * a + (k4 / n)
-- a{1 - (k1/k2)(k1/n)} = (k1/k2)(k4/n) + (k3/k2)
a = ((k1/k2)*(k4/n)+(k3/k2))/(1-(k1/k2)*(k1/n))
b = (k1/n)*a+k4/n
print(string.format("%.8f %.8f", b, a))
sum = 0
for i = 0, n - 1 do
    sum = sum + (a * i + b - t[i + 1])^2
end
print(sum)