The problem about the healer and the chain with which he is trying to pay off

If you cut only one ring, the healer will have the same sawn ring and a chain containing 10 ring-links. On the second day, he will not be able to pay off the owner, and he will drive him out of the yard for non-compliance with the terms of the contract.

This means that there should be at least two cuts. One sorcerer has already done it, now he needs to make the second one on a chain containing 10 rings.

The correct solution would be to saw the fourth ring of the chain: this way the medicine man will receive one sawn ring, a chain of three rings and a chain of six rings. And we must remember that he already had one sawn ring.

Here's how the witch doctor will pay:

1st day: one ring;
2nd day: one ring;
3rd day: a chain of three rings, the owner gives two change rings;
4th day: one ring;
5th day: one ring;
6th day: a chain of six rings, the owner gives five rings of change (two separate and a chain of three rings);
7th day: one ring;
8th day: one ring;
9th day: chain of three rings, the owner gives two rings delivery;
10th day: one ring;
11th day: one ring.

The task is based on of this material.