#!/usr/bin/env python3

import numpy


def solve(n, qs):
    res = numpy.polyfit(list(range(n)), qs, 1, full=True)
    return res[0][1], res[0][0], res[1][0]
    


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


if __name__ == '__main__':
    main()