#include <iostream>

 #include <cstdio>

 #include <cstring>

 #include <vector>

 using namespace std;

 const int N=1e5+;//若在函数内开过大数组，会显示Process returned -1073741571 (0xC00000FD)错误！

 string s;

 vector<char> v[*N];

 int main()

 {

     std::ios::sync_with_stdio(false);//加快cin,cout效率

     std::cin.tie();

 //    freopen("btext.txt","r",stdin);

     while (cin>>s)

     {

         int st=N,h=N-,e=N+;//st为当前光标，h为头，e为尾

         for (int i=;i<*N;i++)

         {

             v[i].clear();

         }

         for (unsigned int i=;i<s.length();i++)

         {

             if (s[i]=='[')

             {

                 st=h;

                 h--;

                 continue;

             }

             if (s[i]==']')

             {

                 st=e;

                 e++;

                 continue;

             }

             v[st].push_back(s[i]);

         }

         for (int i=h;i<=e;i++)

         {

             for (unsigned int j=;j<v[i].size();j++)

             {

                 cout<<v[i][j];

             }

         }

         cout<<endl;

     }

     return ;

 }