abc-ab-c=270
abc- 301- => a=3 ;b=0 ;c=1....=>301-30-1=270
ab 30
c 1
----- ------ ; alte nr.=302=> a=3 ;b=0 ;c=2...abc=302; ab=30; c=2
270 270 304.....=>304-30-4=270
305.........305-30-5=270
306.........306-30-6=270
307.........307-30-7=270
308.........308-30-8=270
309=>a=3 ;b=0 ;c=9....abc=309 ;ab=30 ;c=9
