#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;
struct hehe
{
	int num;
	string ss;
}q[20];
string s,tmp;
int n=0;
int main()
{
	freopen ("passworda.in","r",stdin);
	freopen ("passworda.out","w",stdout);
	cin>>s;
	s='['+s+']';
	for (int i=0;i<s.size();i++)
	{
		if (s[i]=='[')
		{
			n++;
			q[n].num=0;
			q[n].ss.clear();
			continue;
		}
		if (s[i]>='0'&&s[i]<='9')
		{
			q[n].num+=s[i]-'0';
			if (s[i+1]>='0'&&s[i+1]<='9')
			{
				q[n].num*=10;
				q[n].num+=s[i+1]-'0';
				i++;
			}
			continue;
		}
		if (s[i]>='A'&&s[i]<='Z')
		{
			while (s[i]>='A'&&s[i]<='Z')
			{
				q[n].ss+=s[i];
				i++;
			}
			i--;
			continue;
		}
		if (s[i]==']')
		{
			tmp=q[n].ss;
			for (int j=0;j<q[n].num-1;j++)
			{
				q[n].ss+=tmp;
			}
			n--;
			q[n].ss+=q[n+1].ss;
		}
	}
	cout<<q[0].ss;
	return 0;
}