def METHOD_NAME(x, fs, cutoff=70):
    """FUNCTION TO APPLY LOW CUT FILTER
    Args:
        x (ndarray): Waveform sequence
        fs (int): Sampling frequency
        cutoff (float): Cutoff frequency of low cut filter
    Return:
        (ndarray): Low cut filtered waveform sequence
    """
    nyquist = fs // 2
    norm_cutoff = cutoff / nyquist
    # low cut filter
    fil = firwin(255, norm_cutoff, pass_zero=False)
    lcf_x = lfilter(fil, 1, x)
    return lcf_x