import re


def func(in_str):
    print('-------')
    print('in : ' + in_str)
    print('out:')
    print(in_str)
    s = in_str
    while True:
        in_str = re.sub(r'(.)\1{3,}', '', in_str, 1)
        if in_str == s:
            return
        print(in_str)
        s = in_str

if __name__ == '__main__':
    func('11233344433331111143322211')
    func('1122224411112222')
    func('211222211333312')