Merkkijono

def replace():
    global a
    s1 = ""
    for i in range(len(a)):
        if s1 == a[i]:
            for j in range(i+1, len(a)):
                if s1 != a[j]:
                    a = a[:i - 1] + a[j:]
                    return True
            a = a[:i - 1] + a[i+1:]
            if a == s1:
                a = ""
            return True
        s1 = a[i]
    return False

a = input()

while True:
    if not replace():
        break

print(a)

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

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