import numpy as np

def main():
    a = list(map(int, input().split()))
    if a == [0,0,0]:
        print(-1)
    else:
        ans = np.roots(a)
        if len(ans) == 0 or ans[0] != float(ans[0]):
            print(0)
        elif ans[0] != ans[1]:
            print(len(ans))
            for x in ans:
                print("{:.20f}".format(x))
        else:
            print(1)
            print("{:.20f}".format(ans[0]))


if __name__ == "__main__":
    main()