s = input().split()
a = int(s[0])
b = int(s[1])
c = int(s[2])
if a == 0 : 
    if b == 0 :
        if c == 0 : print(-1)
        else : print(0)
    else : print(1, -c / b, sep = '\n')
else :
    if a < 0 :
        a = -a
        b = -b
        c = -c
    d = b * b - 4 * a * c
    if d > 0 : 
        d **= 0.5
        print(2, (-b - d) / (a * 2), (-b + d) / (a * 2), sep = '\n')
    elif d < 0 : print(0)
    else : print(1, -b / (a * 2), sep = '\n')