How can I fast the first ten days of Dhu al-Hijjah after having been menstruating during the first few of them?

If the woman asking the question has purified herself from her menstruation, she should begin fasting the remainder of the first nine days of Dhul-Hijjah; for what cannot be achieved in its entirety should not be abandoned in its majority. However, if menstruation continues, her fasting is not valid until purification.