#include<cstdio> 
#include<cstring>
const int maxn = 100005;
int last,cur,next[maxn];
char s[maxn];
int main(){
    while(scanf("%s",s+1)==1){
        int n = strlen(s+1);
        last = cur = 0;
        next[0] = 0;
        for(int i=1;i<=n;i++){
            char ch = s[i];
            if(ch=='[')cur = 0;
            else if(ch==']')cur = last;
            else{
                next[i] = next[cur];
                next[cur] = i;
                if(cur==last)last = i;
                cur = i;
            }
        }
        for(int i=next[0];i!=0;i=next[i])
            printf("%c",s[i]);
        printf("\n");
    }
    return 0;
}