#include <bits/stdc++.h>

using namespace std;

string expand() {
    int d;
    char x;
    string s;
    while (cin >> x) {
        if (x == '[') {
            cin >> d;
            string t = expand();
            while (d--) s += t;
        } else if (x == ']')
            return s;
        else s += x;
    }
    return s;
}


int main() {
    cout << expand();
    return 0;
}