#include <bits/stdc++.h>
using namespace std;
string ans = "";
char ch; 
string solve () {
//	cout << "Jin";
	ch = getchar();
	int temp = ch - 48;
	string str = "", str1 = "";
	ch = getchar();
	while (ch != EOF){
		if (ch == '['){
			str1 += solve();
		}
		else if(ch == ']'){
			for(int i=1;i<=temp;i++){
				str += str1;
			}
		}
		else {
			str1 += ch;
		}
		ch = getchar();
	}
//	cout << str << "JINN";
	return str;
}
int main(){
	ch = getchar();
	while (ch != EOF){
		if (ch != '[')
			ans += ch;
		else {
			ans += solve();
//          cout << "CHU";
		}
		ch = getchar();
	}
	cout << ans;
	return 0;
}