A cement company has three factories which transport cement to four distribution centres. The daily production of each factory, the demand at each distribution centre, and the associated transportation cost per tonne from factory to distribution centre are given in the Table.


| Activity | A | B | C | D | E |
| Duration (week) | 5 | 6 | 8 | 3 | 4 |
| Crashing cost per week (lakh INR) | 4.0 | 2.5 | 2.0 | 3.0 | 4.0 |
A project network consists of the following activities
\[\begin{array}{|c|c|c|} \hline \textbf{Activity} & \textbf{Immediate Predecessors} & \textbf{Duration (days)} \\ \hline \text{A} & \text{--} & 3 \\ \hline \text{B} & \text{--} & 4 \\ \hline \text{C} & \text{A, B} & 5 \\ \hline \text{D} & \text{B} & 6 \\ \hline \text{E} & \text{D} & 7 \\ \hline \text{F} & \text{C, E} & 8 \\ \hline \text{G} & \text{D} & 9 \\ \hline \text{H} & \text{F, G} & X \\ \hline \end{array}\]
If the project completion time is 30 days, then the value of \( X \), in days, is \(\underline{\hspace{2cm}}\) (in integer).