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