import math
def sieve (n):
	check = [1]*(n+1)
	check[0] = check[1] = 0
	for d in xrange(2,int(math.sqrt(n))+1):
		if check[d] == 0: continue
		for comp in xrange(d*2,n+1,d):
			check[comp] = 0
	return check
N,L = map(int,raw_input().split())
if L < 5:
	print 0
	quit()
prime = sieve(L/(N-1)+1)
M = 0
for i in xrange(2,L/(N-1)+1):
	if prime[i] == 0:
		continue
	if i * (N-1) <= L:
		M += L+1 - i*(N-1)
print M