Merkkijono

import re

def replaceNext(string):
    (tmp, replaced) = re.subn(r'(.)\1+', r'', string, 1)
    if replaced == 0:
        return tmp
    else:
        return replaceNext(tmp)

print(replaceNext(input()))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED