def test_0(): assert countX("xxhixx") == 4
def test_6(): assert countX("hihi") == 0
def test_5(): assert countX("") == 0
def test_4(): assert countX("x") == 1
def test_3(): assert countX("h") == 0
def test_2(): assert countX("hi") == 0
def test_0(): assert countX("xxhixx") == 4
def test_6(): assert countX("hihi") == 0
def test_5(): assert countX("") == 0
def test_4(): assert countX("x") == 1
def test_3(): assert countX("h") == 0
def test_2(): assert countX("hi") == 0