a,b,c = map(int,input().split())
if a == 0:
    if b == 0:
        if c == 0:
            print(-1)
        else:
            print(0)
    else:
        print(1)
        print(-c/b)
else:
    d = b * b - 4 * a * c
    if d == 0:
        print(1)
        print(-b/2/a)
    elif d < 0:
        print(0)
    else:
        qd = d ** 0.5
        print(2)
        ans = [(-b-qd)/2/a,(-b+qd)/2/a]
        ans.sort()
        for a in ans:
            print(a)