limit = 10**5
distinct_prime_factor_count = [0]*(limit+1)
primes = []
for i in range(2, limit+1):
    if distinct_prime_factor_count[i] == 0:
        primes.append(i)
        for num in range(i, limit+1, i):
            distinct_prime_factor_count[num] += 1

N = int(input())
ans = set()

for prime in primes:
    for j in range(2, 63):
        if prime**j <= N:
            ans.add(prime**j)
        else:
            break

print(sum(ans))