N = int(input())
src = list(map(int,input().split()))
mu_x = (N-1) / 2
mu_y = sum(src) / N

sq_sigma_x = 0
for x in range(N):
    sq_sigma_x += (x - mu_x)**2
sq_sigma_x /= N

e_xy = sum([x*y for x,y in enumerate(src)]) / N
cov = e_xy - mu_x*mu_y

d = cov / sq_sigma_x
bi = mu_y - d*mu_x
cost = 0
for i,a in enumerate(src):
    cost += (a - (bi+i*d))**2

print(bi,d)
print(cost)