P = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97]

A,B = map(int,input().split())

ans = 0

for x in P:
    if A <= x <= B:
        ans += x**3 - x**2 + x + 1

print (ans)