import numpy as np

def solve2(a, b, c):
    D = (b**2 - 4*a*c) ** (1/2)
    x_1 = (-b + D) / (2 * a)
    x_2 = (-b - D) / (2 * a)

    return [x_1, x_2]

def main():
    a = list(map(int, input().split()))
    if a == [0,0,0]:
        print(-1)
    elif a[0] != 0:
        ans = solve2(*a)
        if type(ans[0]) is not float:
            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()