Merkkijono

from itertools import groupby
f = lambda s: (lambda k: k if len(k) == len(s) else f(k))("".join(a for a, b in groupby(s) if len(list(b)) == 1))
print(f(input("")))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 3, in <module>
    print(f(input("")))
  File "input/code.py", line 2, in <lambda>
    f = lambda s: (lambda k: k if len(k) == len(s) else f(k))("".join(a for a, b in groupby(s) if len(list(b)) == 1))
  File "input/code.py", line 2, in <lambda>
    f = lambda s: (lambda k: k if len(k) == len(s) else f(k))("".join(a for a, b in groupby(s) if len(list(b)) == 1))
  File "input/code.py", line 2, in <lambda>
    f = lambda s: (lambda k: k if len(k) == len(s) else f(k))("".join(a for a, b in groupby(s) if len(list(b)) == 1))
  File "input/code.py", line 2, in <lambda>
    f = lambda s: (lambda k: k if len(k) == len(s) else f(k))("".join(a for a, b in groupby(s) if len(list(b)) == 1))
  File "input/code.py", line 2, in <lambda>
    f = lambda s: (lambda k: k if len(k) == len(s) else f(k))("".join(a for a, b in groupby(s) if len(list(b)) == 1))
  File "input/code.py", line 2, in <lambda>
    f = lambda s: (lambda k: k if len(k) ==...

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED