Input: data: array with $n$ integers

Input: $n$ : size of data

Algorithm: RecursionMystery

if $n=1$ then

return $0$

else if $n=2$ then

return data$[2]-$ data$[1]$

else

quart $=|\frac{n}{4}|$

half $=|\frac{n}{2}|$

fourths $=$

data$[1..$quart