#include<bits/stdc++.h>
using namespace std;
string y;
int x=0;
string f()
{
	string a="",b="";
	char c;
	int d=0;
	while(x<=y.size())
	{
		c=y[x];
		x++;
		if(c=='[')
		{
			d=y[x]-48;
			x++;
			a=f();
			while(d--)
			{
				b=b+a;
			}
		}
		else if(c==']')
		{
			return b;
		}
		else b=b+c;
	}
}
int main()
{
	cin>>y;
	cout<<f();
	return 0;
}