MathNet 2021 — Part 03 Question 42

The number $1$ is written on the blackboard. A *turn* consists of wiping out the number on the board and replacing it by the double of the number, or by the number one smaller. For example, we can replace $1$ by $2$ (the double) or $0$ (one smaller), and if $5$ is on the board, we can replace it by $10$ or $4$.
What is the minimum number of turns needed in order to write the number $2021$ on the board?