a, b, c = map(int, input().split())
d = b**2 - 4*a*c
if (a,b,c) == (0, 0, 0):
    print(-1)
elif d < 0:
    print(0)
elif d == 0:
    print(1)
    print(-b / 2 / a)
else:
    print(2)
    print((-b - d**2) / 2 / a)
    print((-b + d**2) / 2 / a)