#!/usr/bin/python2
# -*- coding: utf-8 -*-
# †
from decimal import *

def f(a, b, c):
    if a == 0:
        if b == 0:
            return [-1] if c == 0 else [0]
        return [1, -c/b]
    else:
        D = b*b - 4*a*c
        if D < 0:
            return [0]
        if D == 0:
            return [1, -b/(2*a)]
        return [2, (-b-D.sqrt())/(2*a), (-b+D.sqrt())/(2*a)]


a, b, c = map(Decimal, raw_input().split())
res = f(a, b, c)
print res[0]
for token in sorted(res[1:]):
    print '{:.30f}'.format(token)