Question

Trapezium Order

you are given an integer N . print N rows starting from 1 in the trapexium order as shown in the output of the below examples .

Input

the input contains an integer N

OUTPUT

the output should have N lines

each of the N lines should have space -seperated integers as per the trapezium order

SAMPLE INPUT 1

4

SAMPLE OUTPUT 1

1 2 3 4 17 18 19 20

5 6 7 14 15 16

8 9 12 13

10 11

Answer 1

n = int(input())
k = 1
res = []
for i in range(n):
	res.append(" ".join([str(j) for j in range(k, k+n-i)]))
	k += n-i


for i in range(n):
	res[-1-i] += " " + " ".join([str(j) for j in range(k, k+1 + i)])
	k += 1 + i
print(*res, sep="\n")