l = [1, 3, 5, 6, 7, 8, 2, 4]
n = len(l)      # n = ____
a = l[3]        # a = ____
b = l[-1]       # b = ____
a = a + 1       # a = ____
b = a + b       # b = ____
l.append(5)     # l = ___________________
l.append(b)     # l = ___________________
l[0] = 8        # l = ___________________
del l[2]        # l = ___________________