The ADU ball is any integer n greater than or equal to 60,

It can be decomposed into the sum of several 1 1 7 (this is what you want to prove).

That is n= 1 1x+7y.

For example, 60 =1/kloc-0 /×1+7× 7.

The proof and reasoning process, the second picture and it are very detailed, so I won't go into details.