(3000+3000):3+(2000-2000)-(1000+1000):2=1000
(3000+3000)=6000:3=2000
(2000-2000)=0
2000+0=2000
(1000+1000)=2000:2=1000
2000-1000=1000
(3000+3000):3+(2000-2000)-(1000+1000):2=1000
(3000+3000)=6000:3=2000
(2000-2000)=0
2000+0=2000
(1000+1000)=2000:2=1000
2000-1000=1000