#include <bits/stdc++.h>
using namespace std;
string man(){
	int k;
	char c;
	string s = "", ss = "";
	while(cin >> c){
		if(c == '['){
			cin>>k;
			ss=man();
			while(k--)s+=ss;
		}else if(c==']')return s;
		else s+=c;
	}
    return s;
}
int main(){
	cout<<man();
	return 0; 
}