<?xml version="1.0" encoding="UTF-8"?>
<out>: Test for source tree numbering
1: Level A
1+1: Level B
1+2: Level B
1+2-1: Level C
1+3: Level B
1+3-1: Level C
1+3-1-1: Level D
2: Level A
2+1: Level B
2+1-1: Level C
2+1-1-1: Level D
2+1-1-1-1: Level E
3: Level A
3+1: Level B
3+1-1: Level C
3+1-1-1: Level D
3+1-1-1-1: Level E
3+1-1-2: Level D
3+1-1-2-1: Level E
3+1-2: Level C
3+1-2-1: Level D
3+2: Level B
</out>