from typing import List, Tuple def quadratic_solver(A: float, B: float, C: float) -> Tuple[int, List[float]]: """A*x^2 + B*x + C = 0 返回解的个数和解的列表(-1表示无穷多个解) """ if B < 0: A = -A B = -B C = -C if A == 0: if B == 0: if C == 0: return -1, [] # 无穷多个解 return 0, [] # 无解 return 1, [-C / B] D = B * B - 4 * A * C if D < 0: return 0, [] if D == 0: return 1, [-B / (2 * A)] res1 = (-B - D**0.5) / (2 * A) res2 = C / A / res1 if res1 > res2: res1, res2 = res2, res1 return 2, [res1, res2] if __name__ == "__main__": # https://yukicoder.me/problems/no/955%3E a, b, c = map(float, input().split()) n, res = quadratic_solver(a, b, c) if n == -1: print(-1) else: print(n) for x in res: print(x)