# Shipping and Receiving

You are given a two-dimensional list of integers `ports`

where `ports[i]`

represents the list of ports that port `i`

is connected to. You are also given another two-dimensional list of integers `shipments`

where each list of the form `[port_i, port_j]`

which means there is a shipment request from `port_i`

to `port_j`

.

Given that the cost to ship `port_i`

to `port_j`

is the length of the shortest path from the two ports, return the total cost necessary to send all the shipments. If there’s not a path between two ports, the cost is `0`

.

**Constraints**

`p ≤ 100`

where`p`

is the length of`ports`

`s ≤ 10,000`

where`s`

is the length of`shipments`

https://binarysearch.com/problems/Shipping-and-Receiving

## Examples

### Example 1

**Input**

- ports =

```
[[list([2, 3]),list([2]),list([1, 0]),list([4]),list([])]]
```

- shipments =

```
[[2,4]]
```

**Output**

- answer =
`3`

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