João João

In 2025, the person responsible for coordinating the team that creates the OBI – Online Battle of Influencers – exam is Professor João João, who, in addition to being a professor, is a famous and influential influencer.

So far, the team has created $10$ tasks, and each task has been categorized into one of four difficulty levels: $1$, $2$, $3$, and $4$.

Professor João João wants to know how many more tasks need to be created so that it is possible to assemble an exam with exactly four tasks, each at a different difficulty level.

Given the list of difficulty levels of the tasks already created, can you help Professor João João determine how many tasks still need to be created?

The input consists of a single line containing $10$ integers $D_1, \dots , D_{10}$, where $D_i$ denotes the difficulty level of task $i$ ($1 ≤ D_i ≤ 4$, for $1 ≤ i ≤ 10$).

Your program should print a single line to the output, containing a single integer: the minimum number of tasks that need to be created so that it is possible to assemble an exam with four tasks, each at a different difficulty level.