22
(((DF)(GH))(E(E((((CI)D)(N((BL)K)))(J((((QM)(T(SR)))A)(PO)))))))
A rec rec
B bur rec
C rup rec
D brt rec
E ypr rec
D prb rec
E zan rec
F ypr rec
G prb rec
H prb rec
I rec rec
J ypr rec
K brt rec
L rec rec
M lan rec
N bur rec
O ser rec
P rec rec
Q brt rec
R tor rec
S pia rec
T rup rec