disapearingPairs

string solution(string &S) {
    // write your code in C++14 (g++ 6.2.0)

for (short i=0; i<S.length(); i++) {
    if (S[i]==S[i-1]) {
        S.erase(i-1, 2);
        i=0;
        }
}


return S;
}