2

Part of 1993 Czech And Slovak Olympiad IIIA

Problems(1)

integers in fields of a 19 x 19 table

Source: Czech And Slovak Mathematical Olympiad, Round III, Category A 1993 p2

19 \times 19

table are written integers so that any two lying on neighboring fields differ at most by

2

(two fields are neighboring if they share a side). Find the greatest possible number of mutually different integers in such a table.