import math
def sieve(n):
    is_prime=[True]*(n+1)
    is_prime[0]=is_prime[1]=False
    for i in range(2,int(math.isqrt(n))+1):
        if is_prime[i]:
            for j in range(i*i,n+1,i):
                is_prime[j]=False
    return [i for i,prime in enumerate(is_prime) if prime]

N=int(input())
S=sieve(100000)
ans=0
for p in S:
    cur=p*p
    while True:
        if cur>N:
            break
        ans+=cur
        cur*=p
print(ans)