In the network shown below there are nineteen routers between the source$($S$)$ and the destination $($D$).$ It is known that each link has the length of $100km$ and the signal travels at the rate of $2**{10}^8$ meters$/$second on all the links. The bandwidth of each of the links is $1Mbps.$ If a single packet of length $1000$ bits travels from S to D$,$ what is the total delay this packet will experience? Ignore the processing delays.