input: def calc_derivative(coeffs: list):
      """ coeffs represent coefficients of a polynomial.
      coeffs[0] + coeffs[1] * x + coeffs[2] * x^2 + ....
      Return the derivative of this polynomial in the same form.
      >>> calc_derivative([3, 1, 2, 4, 5])
      [1, 4, 12, 20]
      >>> calc_derivative([1, 2, 3])
      [2, 6]
      """
output:     derivative = []
      for i in range(1, len(coeffs)):
          derivative.append(coeffs[i] * i)
      return derivative