Lidgren.Network.NetBigInteger.FastModInverse C# (CSharp) Метод

        private static long FastModInverse(
			long v,
			long m)
        {
            if (m < 1)
                throw new ArithmeticException("Modulus must be positive");

            long[] x = new long[2];
            long gcd = FastExtEuclid(v, m, x);

            if (gcd != 1)
                throw new ArithmeticException("Numbers not relatively prime.");

            if (x[0] < 0)
            {
                x[0] += m;
            }

            return x[0];
        }