nvn [ [ nvn
P XFRO XFST WFRO WFST
Q POFRO POFST POFOO POFPT
3 PPFRO PPFST PPFOO PPFPT
S PRFRO PRFST PRFOO PRFPT
T PTFTO PUFOT PTFRO PTFST
U PVFOO PVFPT PUFPT PUFRO