how long the train ride will be from exton station to 30th street ?
O O O B-SL_METHOD_TRAVEL I-SL_METHOD_TRAVEL O O O B-SL_SOURCE_IN_GET_LOCATION_SL_POINT_ON_MAP I-SL_SOURCE_IN_GET_LOCATION_SL_POINT_ON_MAP O B-SL_DESTINATION I-SL_DESTINATION O