M-(509)=2380
m=2380+509
m=2889
2889-(509)=2380
6000-(n+495)=4730
n=6000-4730
n=1270
n=1270:2
n=635
6000-(635+495)=4730
5682+7387-p=6050
5682+7387=13069
p=13069-6050
p=7019
5682+7387-7019=6050
r+1908+13700=46302
46302-13700=32602
r=32602-1908
r=30694
30694+1908+13700=46302