def test_1():
    assert pairStar("xxyy") == "x*xy*y"
def test_9():
    assert pairStar("abbba") == "ab*b*ba"
def test_0():
    assert pairStar("hello") == "hel*lo"
def test_7():
    assert pairStar("noadjacent") == "noadjacent"
def test_6():
    assert pairStar("") == ""
def test_5():
    assert pairStar("a") == "a"
def test_4():
    assert pairStar("aa") == "a*a"
def test_3():
    assert pairStar("aaab") == "a*a*ab"