#include <bits/stdc++.h>

using namespace std;

using i64 = int64_t;

const i64 MOD = 1e9+7;

const i64 INF = i64(1e18)+MOD;

template <typename T = i64>
struct Range{
    struct iterator{
        T value;
        const T step, last;
        const T& operator*(){return value;}
        iterator(T value, T step, T last) :
            value(step < static_cast<T>(0) ? max(last, value) : min(last, value)),
            step(step),
            last(last)
        {
        }
        iterator operator++(){value = step < static_cast<T>(0) ? max(value + step, last) : min(value + step, last); return *this;}
        bool operator!=(const iterator& x){return value != x.value;}
    };
    const T start, last, step;

    Range(const T start, const T last, const T step = static_cast<T>(1)) :
        start(start),
        last(last),
        step(step)
    {
    }

    Range(const T last) :
        start(0),
        last(last),
        step(1)
    {
    }

    iterator begin(){return iterator(start, step, last);}
    iterator end(){return iterator(last, step, last);}
};

template <typename F>
struct FixPoint{
    const F _f;
    FixPoint(F&& f) : _f(forward<F>(f)){}

    template<typename... Types>
    decltype(auto) operator()(Types&&... args) const{
        return _f(*this, forward<Types>(args)...);
    }
};

template <typename F>
static decltype(auto) makeRec(F&& f){
    return FixPoint<F>(forward<F>(f));
}

template <typename T, T Value = T()>
vector<T> makeVector(size_t x){
    return vector<T>(x, T(Value));
}

template <typename T, T Value = T(), typename... Types>
auto makeVector(size_t x, Types... args){
    return vector<decltype(makeVector<T, Value>(args...))>(x, makeVector<T, Value>(args...));
}

template <typename T = i64>
bool chmax(T& a, T b){
    if(a < b){
        a = b;
        return true;
    }
    return false;
}

template <typename T = i64>
bool chmin(T& a, T b){
    if(a > b){
        a = b;
        return true;
    }
    return false;
}

#define dump(x) fprintf(stderr, "line =%4d, name =%7s , ", __LINE__, #x); clog << "value = " << x << endl;

#define vecdump(x) fprintf(stderr, "line =%4d, name =%7s\n", __LINE__, #x); _dump_macro(x);

void _dump(int, string& x){
    clog << x << endl;
}

template <typename T>
void _dump(bool, T& x){
    clog << x << " ";
}

template <typename T, typename U = typename T::iterator>
void _dump(int, T& x){

    for(auto& elm : x)
        _dump(0, elm);

    clog << endl;
}

template <typename T>
void _dump_macro(T& x){
    _dump(0, x);
}

void _input(int, string& x){
    cin >> x;
}

template <typename T>
void _input(bool, T& x){
    cin >> x;
}

template <typename T, typename U = typename T::iterator>
void _input(int, T& x){

    for(auto& elm : x)
        _input(0, elm);
}

template <typename T>
void input_single(T& x){
    _input(0, x);
}

auto input(){}

template <typename T, typename... Types>
void input(T& value, Types&&... args){
    input_single(value);
    input(forward<Types>(args)...);
};

void _pararell_input(size_t){}

template <typename T, typename... Types>
void _pararell_input(size_t index, T& value, Types&&... args){
    input(value[index]);
    _pararell_input(index, forward<Types>(args)...);
}

template <typename... Types>
void pararell_input(size_t count, Types&&... args){
    for(const auto& i : Range<>(count))
        _pararell_input(i, forward<Types>(args)...);
}

string bnf(string& s){

    string nil = "~";
    string nil2 = "!";

    function<string(int,int)> cip;
    function<string(int,int)> str;
    function<string(int,int)> let;

    int n = s.size();
    vector<vector<vector<string>>> tmp(3, vector<vector<string>>(n + 1, vector<string>(n + 1, nil2)));

    cip = [&](int l, int r){

        if(l >= r || l < 0 || r > n)
            return nil;

        auto& tm = tmp[0][l][r];
        if(tm != nil2)
            return tm;

        auto c = str(l, r);
        if(c != nil)
            return tm = c;

        for(int i = l + 1; i < r; ++i){
            auto c1 = cip(l, i);
            auto c2 = str(i, r);
            if(c1 != nil && c2 != nil)
                return tm = (c1 + c2);
        }
        return tm = nil;
    };

    str = [&](int l, int r){

        if(l >= r || l < 0 || r > n)
            return nil;

        auto& tm = tmp[1][l][r];
        if(tm != nil2)
            return tm;

        if(s[l] == '['){
            auto c = cip(l + 1, r - 1);
            reverse(c.begin(), c.end());
            return tm = c;
        }
        return tm = let(l, r);
    };

    let = [&](int l, int r){

        if(l >= r || l < 0 || r > n)
            return nil;

        auto& tm = tmp[2][l][r];
        if(tm != nil2)
            return tm;

        if(s[l] == '+' && r - l >= 2){
            auto ret = let(l + 1, r);
            if(ret == nil)
                return tm = nil;
            if(ret[0] == 'Z')
                return tm = string("A");
            else
                return tm = string{char(ret[0] + 1)};
        }
        if(s[l] == '-' && r - l >= 2){
            auto ret = let(l + 1, r);
            if(ret == nil)
                return tm = nil;
            if(ret[0] == 'A')
                return tm = string("Z");
            else
                return tm = string{char(ret[0] - 1)};
        }
        return tm = (r - l == 1 && 'A' <= s[l] && s[l] <= 'Z' ? string{s[l]} : nil);
    };

    auto ans = cip(0, n);
    return ans;
}

bool solve(){

    string s;
    input(s);
    if(s == ".")
        return false;

    vector<int> q;
    for(int i = 0; i < int(s.size()); ++i)
        if(s[i] == '?')
            q.emplace_back(i);

    for(auto& p : q){
        int ch = 0;
        for(int i = p - 1; i >= 0; --i){
            if(s[i] == '+')
                --ch;
            else if(s[i] == '-')
                ++ch;
            else
                break;
        }
        while(ch < 0)
            ch += 26;
        while(ch >= 26)
            ch -= 26;
        s[p] = char(ch + 'A');
    }

    cout << bnf(s) << endl;

    return true;
}

signed main(){

    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(20);

    while(solve());

}



Measured memory_bytes: 3356