m,l=map(int,input().split())
m-=1
n=l//m
L=list(range(n+1))
a,b=1,2
for i in L[1::2]:
	if L[i]<2:continue
	L[i::i]=n//i*[0]
	a+=1
	b+=i
print(max((l+1)*a-m*b,0))