def LAcum(L):
	a=[]
	s=0
	for i in range(len(L)):
		s += L[i]
		a.append(s)
	return a

def rangosLAcum(L,i,j):
	L2=LAcum(L)
	if not i:return L2(j)
	return L2[j]-L2[i-1]
	

L=[1,2,3,4,5,6,7,8,9,10]

print(rangosLAcum(L,1,3))