Implement a function which behaves like the uniq command in UNIX.
It takes as input a sequence and returns a sequence in which all duplicate elements following each other have been reduced to one instance.
Example:
```
["a", "a", "b", "b", "c", "a", "b", "c"]  =>  ["a", "b", "c", "a", "b", "c"]
```
def uniq(seq):
    if len(seq) == 0:
        return []
    rez = [seq[0]]
    for i in range(1, len(seq)):
        if seq[i] != rez[-1]:
            rez.append(seq[i])
    return rez
def uniq(seq):
    if len(seq) == 0:
        return []
    rez = [seq[0]]
    for i in range(1, len(seq)):
        if seq[i] != rez[-1]:
            rez.append(seq[i])
    return rez