ab=input().split()
a=int(ab[0])
b=int(ab[1])
nums=[]
for i in range(a,b+1):
    prime=1
    for j in range(2,i):
        if i%j==0:
            prime=0
    if i==1:
        prime=0
    if prime==1:
        nums.append(i)
sums=[x**3-x**2+x+1 for x in nums]
print(sum(sums))