The ruling on a woman who married after her husband was lost, and then he returned afterward

Question:
We heard in the lecture that a woman has the right to marry after four years of her husband being lost. The question is: if her original husband returns, what is the ruling? Does she stay with the second husband, or does she return to the first? And if she returns to the first, how is that done?

Answer:
If a person is lost among his people, and it is not known where he is, then the most likely outcome is that he has perished. If he is lost among people in their cities and villages, and it is not known where he went; if four years have passed, as 'Umar ibn al-Khattab ruled, they are separated, she is ordered to observe the waiting period, and she may marry. If her first husband comes, she returns to the court, and the court looks into such a case. The Sharia court looks into their matter.

Question: Is the waiting period four months and ten days?

Answer: Four months and ten days, as if he were dead.