# Parking

Author: aruzhan
Problem has been solved: 190 times

Русский язык | English Language

Along Lenin Street, three free parking spaces are located sequentially. Daniyar, Alen and Nurdaulet ride one after another along this street and try to park. Each of them has one favorite parking space with the number $d$, $a$ and $n$ respectively (where $d$, $a$ and $n$ are numbers from $1$ to $3$, not necessarily different). One after another, each of them arrives at their favorite parking space, and if it is free, parks, otherwise it goes further and gets in the first free place. Find the number of ordered triples of numbers $(d, a, n)$ such that all three can park.