1+2+3+4……+9999999+10000000=（1+10000000）*10000000/2
=50000005000000
-9999-8888-7777-6666-5555-4444-3333-2222-1111=-49 995
则为：50000005000000-49995=50000004950005
1+2+3+4……+9999999+10000000-9999-8888-7777-6666-5555-4444-333
1+2+3+4……+9999999+10000000=（1+10000000）*10000000/2
=50000005000000
-9999-8888-7777-6666-5555-4444-3333-2222-1111=-49 995
则为：50000005000000-49995=50000004950005