#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
string s;
int len,sb;
string l() 
{
	string s1="";
	int sum=0;
	while(s[sb]>='0'&&s[sb]<='9'){
		sum=sum*10+s[sb]-'0';
		sb++;
	}
	while(s[sb]!=']')
	{
		if(s[sb]=='['){
			sb++;
			s1+=l();
		   }
		else{
			s1=s1+s[sb];
			sb++;
		}
	}sb++;
	string hehe="";
	for(int i=1;i<=sum;i++)
	  hehe+=s1;
	return hehe;
}
int main()
{
	freopen("passworda.in","r",stdin);
	freopen("passworda.out","w",stdout);
	cin>>s;
	len=s.size();
	string hehe="";
	while(sb<len)
	{
		if(s[sb]!='[')
		{
		    hehe+=s[sb];
			sb++;
		}
		else
		{
			sb++;
			hehe+=l();
		}
	}
	cout<<hehe;
	return 0;
}