Python-сообщество

 s = str(input())
code = False
for i in range(len(s)):
    try:
        if s[i]==s[i-1]:
            s = s.replace(s[i]*2,'')
            i-=2
            print(s)
            continue
    except:
        pass
print(s)

 class MyIter:
    def __init__(self, end):
        self.current = -1
        self.end = end
    def __iter__(self):
        return self
    def __next__(self):
        if self.current < -1:
            raise StopIteration()
        return self.next()
    def next(self):
        self.current += 1
        if self.current >= self.end:
            raise StopIteration()
        return self.current
    def previous(self):
        self.current -= 2
        return self.current
def test_1():
    assert [x for x in MyIter(3)] == [0, 1, 2]
def test_2():
    flag = False
    l = []
    my_iter = MyIter(5)
    for value in my_iter:
        if not flag and value == 3:
            flag = not flag
            my_iter.previous()
        l.append(value)
    assert l == [0, 1, 2, 3, 2, 3, 4]
def test_3():
    l = []
    my_iter = MyIter(3)
    for value in my_iter:
        my_iter.previous()
        l.append(value)
    assert l == [0]