Terms for subject General containing impossible to understand

English	Russian
impossible to understand	непонятный
it is impossible to understand what he means	непонятно, что он хочет сказать
it's impossible to understand Russia with reason	Умом Россию не понять (ankicadeenka)
that's impossible to understand	который невозможно понять (thenewstack.io Alex_Odeychuk)