#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
string solve()
{
    string s1="",s2;
    char ch;
    while(cin>>ch)
    {
        if(ch=='[')
        {
            int t;
            cin>>t;
            s2=solve();
            while(t--) s1+=s2; 
        }
        else if(ch==']')
		{
			return s1;
		} 
        else s1+=ch;
    }
}
int main()
{
	freopen("extract.in","r",stdin);
    freopen("extract.out","w",stdout);
    cout<<solve();
    return 0;
}