a, b, c = map(int, input().split())
d = b ** 2 - 4 * a * c
if d < 0:
    print(0)
elif a == 0 and b == 0 and c == 0:
    print(-1)    
else:
    x = set()
    x.add((-b - d ** 0.5) / 2 * a)
    x.add((-b + d ** 0.5) / 2 * a)
    print(len(x))
    for v in x:
        print("%.6f" % float(v))

