from decimal import *

def solve2(a, b, c):
    try:
        D = (b**2 - 4*a*c) ** Decimal(1/2)
        x_1 = (-b + D) / (2 * a)
        x_2 = (-b - D) / (2 * a)
    except:
        return [None, None]

    return [x_1, x_2]

def main():
    a = [Decimal(int(x)) for x in input().split()]
    if a == [0,0,0]:
        print(-1)
    elif a[0] != 0:
        ans = solve2(*a)
        if ans[0] is None:
            print(0)
            return
        ans.sort()
        if ans[0] != ans[1]:
            print(len(ans))
            for x in ans:
                print("{:.20f}".format(x))
        else:
            print(1)
            print("{:.20f}".format(ans[0]))
    elif a[1] != 0:
        print(1)
        print("{:.20f}".format(-a[2] / a[1]))
    else:
        print(0)


if __name__ == "__main__":
    main()