common
krs10
krs15

./common:
c1
c2

./common/c1:
a
c

./common/c1/a:
a.c

./common/c1/c:
c.c

./common/c2:
a
b

./common/c2/a:
a.c

./common/c2/b:
b.c

./krs10:
c1
c3

./krs10/c1:
b

./krs10/c1/b:
b.c

./krs10/c3:
test

./krs15:
c1
c3

./krs15/c1:
b

./krs15/c1/b:
bb.c

./krs15/c3:
test2