#!ruby -narprime
e=->n,m{t=1;(1..n).map{|i|t*=(i%m*t)%m};t}
f=->n,m{n<2?1%m:1&n<0?((2**n*f[n,m])%m*(g[n-1,m]%m))%m:(n%m)*(f[n-1,m]%m)%m}
$F[1]&&(
n,m=$F.map &:to_i
if m <= n
  0
elsif Prime.prime? m
  f[n,m]
else
  0
end
)