WAP to print the pattern

if input is 4
pattern is

4 3
1 2

if input is 8
output is

5 4 3
6 1 2
7 8

if input is 19
output is

17 16 15 14 13
18  5  4  3 12
19  6  1  2 11
    7  8  9 10

Write a program to print above pattern?