143165576
 1919020031
 1204252996
 210637432
 724264821
 1741
 619489590
 1199537418
 1075765759
 747976826
 638486017
 58438190
 1285316221
 186925426
 1180540990
 833393692
 1818960378
 2000000000
 0
 1309028227
 514714359
 624205168
 1795248373
 643201595
 1304312649

14 3 3 4 5 2 4 4 2 4 6 4 3 4 5 3 5 4 1 5 3 4 5 5 8
def main():
	n = int(input())
	arr = []
	for i in range(2,n):
		if n % i == 0:
			arr.append(i)
			while n % i == 0:
				n //= i
	if len(arr) == 0:
		print(2)
	elif len(arr) > 2:
		print(sum(map(int,str(arr[len(arr) / 2]))))
	else:
		print(0)


if __name__ == '__main__':
	main()