! lsr4_2 ! (x^50+1)(x^2+ax+a^{-1}) a=10^20 srq 0 52 6 0 1 100000000000000000000 1 100000000000000000000 1 2 1 1 50 1 100000000000000000000 51 100000000000000000000 1 52 1 1