first and foremost; top priority
Idiomatic expression literally meaning 'plot 1, block 1', used to emphasize that something is the most important thing to address first, like the starting point of a plan or policy.
Education reform is the top priority of this administration.
まずは顧客満足が一丁目一番地です。
First and foremost, customer satisfaction is the most important thing.
Standard kanji spelling for the idiomatic expression.
Numerical variant, often seen in addresses or informal writing.
From the address notation '1-chōme 1-banchi', the very first plot in a town, metaphorically extended to mean the starting point or highest priority.