N = int(input())
maxn = 10**6
P = [True] * maxn
for i in range(2, maxn):
    if not P[i]:
        continue
    for j in range(i + i, maxn, i):
        P[j] = False
ps = []
for i in range(2, maxn):
    if P[i]:
        ps.append(i)
a = set()
for e in range(2, 50):
    for v in ps:
        vv = pow(v,e)
        if vv<=N:
            a.add(vv)
        else:
            break

print(sum(a))