Note:
1 Shop can has N Invoice, right ?
Yes, sure !!
1 Shop can has 1 Invoice ?
No, Way or they want to sell only 1 thing per day !!
1 Invoice can come from N Shop ?
Hell No !!, how can they sell item together in 1 building !!
1 Invoice can come from 1 Shop ?
Yes !!!!!!!!!!
Invoice & Shop is non-identifying
Conclusion is
1 (Shop) :N (Invoice) non-identifying