import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N = int(input())
	if N == 3:
		print(2)
		return
	
	n = int((N ** 0.5) // 1)
	# print(n)
	ans = int(N // n)
	D = defaultdict(int)
	for i in range(1, n):
		val = int(N // i)
		D[val] += 1

	ans += len(D)
	print(ans)

if __name__ == '__main__':
	main()