n = int(input())
X = [i for i in range(n)]
Y = list(map(int, input().split()))
dot = sum(x * y for x, y in zip(X, Y))
x2 = sum(x * x for x in X)
y2 = sum(y * y for y in Y)
a = (dot - sum(Y) * sum(X) / n) / (x2 - sum(X) ** 2 / n)
b = (sum(Y) - a * sum(X)) / n

print(b, a)
f = lambda x: a * x + b
d = sum((y - f(x)) ** 2 for x, y in zip(X, Y))
print(d)