sentence: the russian united democratic party '' yabloko '' ( russian : росси́йская объединённая демократи́ческая па́ртия '' я́блоко '' rossiyskaya obyedinyonnaya demokraticheskaya partiya '' yabloko '' ; ( -- '' apple '' ) is a russia social liberal party founded by grigory yavlinsky and currently led by sergey mitrokhin , a former opposition member of the moscow city duma and state duma .