import math
def eratosthenes(n):
    sieve=[True]*(n+1)
    for i in range(int(math.sqrt(n))+1):
        if i<2:
            sieve[i]=False
        elif sieve[i]:
            for j in range(2,n//i+1):
                sieve[i*j]=False
    return sieve
A,B=map(int,input().split())
sieve=eratosthenes(B)
primes=[]
for i in range(A,B+1):
    if sieve[i]:primes.append(i)
def f(x):
    return x**3-x**2+x+1
ans=0
for p in primes:
    ans+=f(p)
print(ans)