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You forgot that these 16 digits have a structure, with the 4 or even 8 first ones being determined by the type (visa, mastercard) and the bank/country, etc.
by henearkr 6y ago
You forgot that these 16 digits have a structure, with the 4 or even 8 first ones being determined by the type (visa, mastercard) and the bank/country, etc.
- nikanj 6y agoThat's a made-up problem, and the right solution is not adding more digits to the cards.