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