import sys
from functools import reduce
from typing import List, Tuple


def int1(x: str, /): return int(x) - 1


def input(): return sys.stdin.readline().rstrip('\n')


def dbg(*args, **kwargs):
    print(*(repr(arg) for arg in args), *(f'{k}: {repr(v)}' for k, v in kwargs.items()),
          sep='; ', file=sys.stderr, flush=True)


def main():
    def isprime(x):
        if x < 2:
            return False
        for i in range(2, x):
            if x % i == 0:
                return False
        return True

    a, b = map(int, input().split())
    print(sum(i ** 3 - i ** 2 + i + 1 for i in range(a, b + 1) if isprime(i)))


def _start():
    ret = main()

    if ret is not None:
        if isinstance(ret, List) or isinstance(ret, Tuple):
            print(*ret)
        else:
            print(ret)


if __name__ == '__main__':
    _start()