void UNPACK(const char* str, FILE* f) {
    int i = 0;
    while (str[i]) {
        if (str[i] == '(') {
            i++;
            int count = 0;
            while ('0' <= str[i] && str[i] <= '9') {
                count = count * 10 + str[i] - '0';
                i++;
            }

            i++;
            for (int j = 0; j < count; j++) {
                fprintf(f, "%c", str[i]);
            }
        }
        else {
            fprintf(f, "%c", str[i]);
            i++;
        }
    }
}