Tawawa

I'll add something here just in case.

Usually, in such problems, people cross from one shore to another in a boat, and therefore the boat must always be on the shore from which the people start their journey. I read the condition of your problem, and I have a question: do you have a conditional "boat"? Can you cross the border several times in one direction in a row, without returning?

Yes, it can be considered that way. In this case, the conditional boat needs to be transported back and forth.

Added 40 minutes later
To make it easier to understand: you need to transport a cart across the border; the cart has two seats, and people, animals, and objects occupy one seat; there must be at least one person in the cart.