# Starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral is formed as follows:
#
#				21 22 23 24 25
#				20  7  8  9 10
#				19  6  1  2 11
#				18  5  4  3 12
#				17 16 15 14 13
#
# It can be verified that the sum of the numbers on the diagonals is 101.
#
# What is the sum of the numbers on the diagonals in a 1001 by 1001 spiral formed in the same way?


def sumOfDiagonals(n):
	return (16*n**3 + 30*n**2 + 26*n + 3) // 3

def main():
	width = 1001
	n = (width - 1) // 2
	sumDiag = sumOfDiagonals(n)
	print(sumDiag)


if __name__ == '__main__':
	main()
