from collections import defaultdict
import sys,heapq,bisect,math,itertools,string
sys.setrecursionlimit(10**8)
INF = float('inf')
mod = 10**9+7
AtoZ = [chr(i) for i in range(65,65+26)]
atoz = [chr(i) for i in range(97,97+26)]

N = int(input())
dp = []

Prime=[2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,\
73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157,\
163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239,\
241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337,\
347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431,\
433, 439, 443, 449, 457, 461, 463, 467, 479, 487, 491, 499, 503, 509, 521,\
523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601, 607, 613, 617, 619,\
631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727,\
733, 739, 743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829,\
839, 853, 857, 859, 863, 877, 881, 883, 887, 907, 911, 919, 929, 937, 941,\
947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013, 1019, 1021, 1031, 1033,\
1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1117,\
1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223,\
1229, 1231, 1237, 1249, 1259]

def Prime_Fact(N):
	i = 2
	prime_tb = []
	while N >= 2:
		if N%i == 0:
			prime_tb.append(i)
			N //= i
			i = 2
		else:
			i += 1
	return list(set(prime_tb))

ans_tb = [0]*1300
ans = 0
for i in range(2,N+1):
	prime_tb = Prime_Fact(i)
	b = []
	for pr in prime_tb:
		b.append(ans_tb[pr])
	bn = sum(set(b))
	if i > bn:
		ans = ans - bn + i
		for pr in prime_tb:
			ans_tb[pr] = i

print(ans)