The number is 1, 2, 5,

15 and 17.

1 The distance from other points is 1, 4, 7, 5.

The distances between 2 and other points are 3, 8 and 6.

The distance between 5 and the following points is10,9.

The distance between 15 and 17 is 2.

There is no repetition.

Because the distance between n points * * * is n(n- 1)/2, the polygon distance of 2 1 is at most 10, so the maximum value cannot exceed 5.