p s x x fac 0 s 0 fac s x times s x fac p s x 2.2 fac s x p s x fac s x fac p s x true 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 2438 p 1 1 p 1 1 0 0 0 0 times 2 2 1 fac 1 1 p s x x fac s x p s x false NaTT certifiable-1.6