s= []
m=100000
pl=[0]*(m+1)
for i in range(2,m+1):
	if pl[i]:continue
	d =2
	while i**d <= 10**10:
		s.append(i**d)
		d+=1
	for j in range(i,m+1,i):
		pl[j]=1
n = int(input())
ans=0
for i in s:
	if i<=n:ans+=i
print(ans)