a+b+c+d=1026,,,a+b=549,,,a+b+c=911,,,b+c+d=796,,,,,,,,,,,,a+b+c=911,,,549+c=911,,,,c=911-549=362,,,,c=362,,,,,,,,,,549+362+d=1026,,,,d=1026-911=115,,,,d=115,,,,,,b+362+115=799,,,b+477=799,,,b=799-477=322,,,,b=322,,,,,,a+b=549,,,,a+322=549,,,,a=549-322=227,,,,,,,,227+322+362+115=1026