def p(n):
	if n < 2:
		return False
	else:
		for i in range(2, int(n/2)+1):
			if n % i == 0:
				return False
			else:
				return True

def f(x):
	return X**3 - x**2 + x + 1
	
A, B = map(int, input().split())
s = 0
for x in range(A, B+1):
	if prime(x):
		s += f(x)

print(s)