import math

l = list(map(float, raw_input().split(" ")))

delta = l[1]*l[1]-4*l[0]*l[2]

if l[0] == 0 and l[1] == 0 and l[2] == 0:
    print("-1")
elif l[0] == 0 and l[1] == 0 or delta < 0:
    print("0")
elif delta == 0:
    print("1")
    print("%.5f" % float((-l[1]) / 2*l[0]))
elif l[0] == 0:
    print("1")
    print("%.5f" % (-l[2]/l[1]))
else:
    a = (-l[1] + math.sqrt(l[1]*l[1] - 4*l[0]*l[2])) / 2*l[0]
    b = (-l[1] - math.sqrt(l[1]*l[1] - 4*l[0]*l[2])) / 2*l[0]

    lt = [a, b] 
    lt.sort();
    
    ot = sorted(set(lt))
    
    print("%d" % len(ot))
    
    for i in range(len(ot)):
         print("%.5f" % ot[i])
