#include<cstdio>
#include<cstring>
const int maxn=100000+5;
int last,cur,next[maxn];
char s[maxn];
int main()
{
#ifdef local
	freopen("pro.in","r",stdin);
#endif
	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;
}
