#include <iostream>
#include <cstring>
using namespace std;

const int maxn = 100000 + 5;
int last,cur,list[maxn] ;
char s[maxn] ;
int main(int argc, char *argv[])
{
    while(scanf("%s",s+1) == 1)
    {
        int len = strlen(s+1);
        last = cur = 0;
        list[0] = 0; //指示位置的链表 
        
        for(int i = 1;i <= len ;i++)
        {
            char ch = s[i] ;
            if(ch == ‘[‘) cur = 0;
            else if(ch == ‘]‘) cur = last ;
            else{
                list[i] = list[cur] ; //光标跳转，指示开头 
                list[cur] = i;
                if(cur == last) last = i ;
                cur = i ; 
            }
        } 
        for(int i = list[0]; i != 0;i = list[i])
            printf("%c",s[i]);
        cout << endl ;
    }
    return 0;
}