import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import numpy as np

# いわゆる最小二乗法

N = int(readline())
x = np.arange(N)
y = np.array(read().split(),np.int64)

mu_x = x.mean(); mu_y = y.mean()

a = np.dot(x - mu_x, y - mu_y) / np.dot(x - mu_x, x - mu_x)

fit_y = a * (x - mu_x) + mu_y
error = ((y - fit_y) ** 2).sum()

print(fit_y[0], a)
print(error)