248*697+635*303+387*197
=248*697+248*303+387*303+387*197
=248*(697+303)+387*(303+197
)=248*1000+387*500
=248000+193500
=441500
248*697+635*303+387*197
=248*697+248*303+387*303+387*197
=248*(697+303)+387*(303+197
)=248*1000+387*500
=248000+193500
=441500