An apparatus includes a first encoder for receiving a plurality of symbol streams for respective ones of a plurality of mobile stations and encoding each of the symbol streams with one of a plurality of covering sequences to form a plurality of covered sequences. A plurality of destinations for the same data input by the input means are designated. Additionally, the generator may be disposable. The target memory cells programmed to their respective target threshold levels during the first pass are not programmed further. Part of Ba constituting the A site is replaced with Bi, Ca, a rare-earth element, and Na.