def clean_data(df):
    """Perform data cleaning

    Parameters
    ----------
    df : pandas.DataFrame
        Input dataframe

    Returns
    -------
    pandas.DataFrame
        Cleaned dataframe
    """
    # 'Jun' is spelt as 'June' in raw data
    df["Month"] = df["Month"].replace("June", "Jun")
    df["Revenue"] = df["Revenue"].astype("int64")

    return df