On the second day for breakfast
you should only drink one glass of yogurt and the lunch is the same as the first day. You skip dinner on the second day.
On the third and last day for breakfast
you will need to eat only one boiled potato (without salt). For lunch you will need to eat one boiled potato (without salt) and one glass of yogurt. The dinner is the same as in the first day – only one glass of yogurt.