Merkkijono

insertation = list(input(""))

def starter(insertation):
    while True:
        asd = in_a_row(insertation)
        insertation = asd[0]
        if asd[1] == True:
            return "".join(insertation)

def in_a_row(insertation):
    for i in range(len(insertation) - 1):
        if insertation[i] == insertation[i + 1]:
            try:
                while insertation[i] == insertation[i + 2]:
                    del insertation[i]
            except:
                pass
            del insertation[i]
            del insertation[i]
            return(insertation, False)
    return insertation, True

print(starter(insertation))

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