It's 5 because it's 5
If you put another number it will not work
All levels numbers :
r1 (rupturefarm) : 1
e1 (stockyards escape) : 5
l1 (monsaic) : 2
f1 (paramonia) : (impossible to edit)
f2 (paramonian temple) : 4
f4 (paramonian temple end) : 14
d1 (scrabania) : 8
d2 (scrabanian temple) : 9
d4 (scrabanian temple end) : 15
e2 (stockyards return) : 6
r2 (rupturefarm return) : 13
r6 (boiler) : 12