Write a function that takes an integer and returns an array `[A, B, C]`, where `A` is the number of multiples of 3 (but not 5) below the given integer, `B` is the number of multiples of 5 (but not 3) below the given integer and `C` is the number of multiples of 3 and 5 below the given integer. 
For example, `solution(20)` should return `[5, 2, 1]`
~~~if:r
```r
# in R, returns a numeric vector
solution(20)
[1] 5 2 1
class(solution(20))
[1] "numeric"
```
~~~
def solution(number):
    number = number - 1
    fizzbuzz = number // 15
    fizz = number // 3 - fizzbuzz
    buzz = number // 5 - fizzbuzz
    return [fizz, buzz, fizzbuzz]
def solution(number):
    number = number - 1
    fizzbuzz = number // 15
    fizz = number // 3 - fizzbuzz
    buzz = number // 5 - fizzbuzz
    return [fizz, buzz, fizzbuzz]