Lista intercalada

from random import randint

l1, l2, l3 = [], [], []

for i in range(5):
    n = randint(1,10)
    l1.append(n)
    l3.append(l1[i])
    n = randint(1,10)
    l2.append(n)
    l3.append(l2[i])

print 'Lista 1:'
for i in range(5):
    print l1[i],

print '\n\nLista 2:'
for i in range(5):
    print l2[i],

print '\n\nLista 3:'
for i in range(10):
    print l3[i],