from decimal import *

getcontext().prec = 1000

a, b, c = map(Decimal, input().split())

if a == b == 0:  # 0次方程式
    if c == 0:
        print(-1)
    else:
        print(0)
elif a == 0:  # 1次方程式
    print(1)
    print(f"{-c / b:.32f}")
else:  # 2次方程式
    D = b**2 - a*c*4
    if D < 0:
        print(0)
    elif D == 0:
        print(1)
        print(-b / (a*2))
    else:
        print(2)
        ans = [(-b - D.sqrt()) / (a*2), (-b + D.sqrt()) / (a*2)]
        ans.sort()
        for a in ans:
            print(f"{a:.32f}")