// yukicoder: No.406 鴨等間隔の法則
// 2019.4.16 bal4u

#include <stdio.h>
#include <math.h>

#define MAX  5000000
char notPrime[MAX+2] = { 1,1,0,0,1 };			// zero: if prime 
void sieve(int max)
{
	int i, j, b;
	b = (int)sqrt((double)max);
	for (i = 3; i <= b; i += 2) {
		if (!notPrime[i]) {
			for (j = i * i; j < MAX; j += i) notPrime[j] = 1;
		}
	}
}

int main()
{
	int i, k, s, N, L, max;
	long long ans;

	scanf("%d%d", &N, &L);
	max = L / (N - 1);
	sieve(max);
	ans = 0;
	if (2 <= max) ans = L+1 - ((N-1) << 1);
	k = s = 0;  for (i = 3; i <= max; i += 2) {
		if (!notPrime[i]) k++, s += i;
	}
	if (k) ans += (long long)k * (L + 1) - (long long)(N - 1)*s;
	printf("%lld\n", ans);
	return 0;
}