#include<bits/stdc++.h>//unsigned 
using namespace std;
string answer() {
	string a="",b;
	char q;
	while(cin>>q) {
		if(q=='[') {
			int q;
			cin>>q;
			b=answer();
			for(int i=1; i<=q; i++) {
				a+=b;
			}
		}
		else {
			if(q==']') {
				return a;
			}else{
				a+=q;
			}
		}
	}
}
int main() {
	cout<<answer();
	return 0;
}