#include <stdio.h>
#include <string.h>

#define N 10000000
//#define N 100

int nprimes;
int primes[N];
int divisor[N+1];

void find_primes()
{
	memset(divisor, 0, sizeof(divisor));
	nprimes = 0;
	for (int i = 2; i <= N/2; i++) {
		if (divisor[i] == 0) {
			primes[nprimes] = i;
			nprimes++;
		}
		for (int j = 0; j < nprimes; j++) {
			int t = i * primes[j];
			if (t > N)
				break;
			divisor[t] = i;
		}
	}
}

int M(int p, int q, int n)
{
	int r = 0;
	long long t1 = p;
	while (t1 < n) {
		long long t2 = t1 * q;
		if (t2 > n)
			break;
		while (t2 * q <= n) {
			t2 *= q;
		}
		if (t2 > r)
			r = t2;
		t1 *= p;
	}
	return r;
}

int ismpqn(int n)
{
	int npf = 0;
	int pf[64];

	if (divisor[n] == 0)
		return 0;

	int t = n;
	while (divisor[t] != 0) {
		int d = t / divisor[t];
		pf[npf] = d;
		npf++;
		while (t % d == 0) {
			t /= d;
		}
	}
	if (t > 1) {
		pf[npf] = t;
		npf++;
	}

	if (npf != 2)
		return 0;

	/* TODO: Maybe it can be optimized, but it looks enough */
	if (M(pf[0], pf[1], N) == n)
		return 1;
	else
		return 0;
}

int main()
{
	long long s = 0;
	find_primes();
	for (int i = 1; i <= N; i++) {
		if (ismpqn(i))
			s += i;
	}
	printf("%lld\n", s);
}