#include<iostream>
#include<cstring>
#include<string>
using namespace std;
string s;
int n;
string ans;
string ChengS(int num,string k)
{
	string tmp="";
	for(int ii=1;ii<=num;ii++)tmp+=k;
	return tmp;
}
//KMA[3L[2WB][2Y]][3EQ]PW
int i=0;
string work()
{
	
	int D=0;
	string tmp="";
	
	while(i<n)
	{
		//cout<<i<<endl;
		if(s[i]=='[')
		{
			i++;
			D=0;
			while(s[i]>='0'&&s[i]<='9')
			{
				D=D*10+int(s[i]-'0');
				i++;
			}
			tmp+=ChengS(D,work());
		}
		else 
		{
			if(i>=n)return tmp;
			if(s[i]==']')
			{
				
				return tmp;
			}
			else 
			{
				if(s[i]>='A'&&s[i]<='Z')
				{
					
					tmp+=s[i];
				}
			}
		}
		i++;
	}
}
		
		
		
		
		
		
int main()
{
	cin>>s;
	n=s.length();
	//cout<<n<<endl;
	cout<<work();

	
}