def xor(list1, list2):
result = []
union = list1 + list2
for x in union:
if x not in list1 or x not in list2:
result += [x]
return result
import ast
a, b = [ast.literal_eval(input()) for _ in range(2)]
print(xor(a, b))
ZGVmIHhvcihsaXN0MSwgbGlzdDIpOgogICAgcmVzdWx0ID0gW10KICAgIHVuaW9uID0gbGlzdDEgKyBsaXN0MgogICAgZm9yIHggaW4gdW5pb246CiAgICAgICAgaWYgeCBub3QgaW4gbGlzdDEgb3IgeCBub3QgaW4gbGlzdDI6CiAgICAgICAgICAgICByZXN1bHQgKz0gW3hdCiAgICByZXR1cm4gcmVzdWx0CgoKaW1wb3J0IGFzdAoKYSwgYiA9IFthc3QubGl0ZXJhbF9ldmFsKGlucHV0KCkpIGZvciBfIGluIHJhbmdlKDIpXQpwcmludCh4b3IoYSwgYikp