a,b=map(int,input().split())
def f(x):
    return x**3-x**2+x+1
def sum_of_function(a,b):
	s=0
	for i in range(a,b+1):
		if i>1:
			for j in range(2,i//2+1):
				if i%j==0:
					break
			else:
				s+=f(i)
	return s
print(sum_of_function(a,b))