#!/usr/bin/env python3


def lsm(n, qs):
    d = n * sum(i * qs[i] for i in range(n)) - sum(range(n)) * sum(qs)
    d /= n * sum(i ** 2 for i in range(n)) - (sum(range(n))) ** 2
    b0 = sum(i ** 2 for i in range(n)) * sum(qs)
    b0 -= sum(i * qs[i] for i in range(n)) * sum(range(n))
    b0 /= n * sum(i ** 2 for i in range(n)) - (sum(range(n))) ** 2
    bs = (b0 + i * d for i in range(n))
    cost = sum((q - b) ** 2 for q, b in zip(qs, bs))
    return b0, d, cost


def main():
    n = int(input())
    qs = [int(q) for q in input().split()]
    b0, d, cost = lsm(n, qs)
    print("{:.12f} {:.12f}".format(b0, d))
    print("{:.12f}".format(cost))


if __name__ == '__main__':
    main()