p s x x fac 0 s 0 fac s x times s x fac p s x times times 2.2 times x y times y x times x times y z times times x y z fac s x p s x fac s x fac p s x fac s x fac p s x true fac 1 1 s 1 1 1 p 1 0 p 1 0 0 0 0 times 2 0 fac 1 0 s 1 1 7720 p 1 1 p 1 1 0 0 0 0 times 2 0 fac 1 1 fac s x fac p s x p s x x fac s x p s x false NaTT certifiable-1.6