a = [1, 2, 1, 13, 5 ,13]
b = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13]
c = []

for i in a:
    if i in c:
        continue
    if i in b:
        c.append(i)

print(c)