Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| km | Municipality | Location | Interescting highway | Notes |
| --- | --- | --- | --- | --- |
| 0 | Canada-United States border | Canada-United States border | ND 18 – Cavalier, Larimore | PTH 30 begins |
| 3 | R.M. of Rhineland | Gretna | PR 243 east – Emerson | begin PR 243 west concurrence |
| 5 | R.M. of Rhineland |  | PR 243 west – Blumenfeld | end PR 243 west concurrence |
| 10 | R.M. of Rhineland |  | PR 421 east – Sommerfeld |  |
| 14 | R.M. of Rhineland | Altona | PR 201 west – Brown, Windygates, Snowflake | begin PR 201 east concurrence |
| 18 | R.M. of Rhineland |  | PR 201 east – Letellier, Dominion City, Stuartburn | end PR 201 east concurrence |
| 25 | R.M. of Rhineland | Rosenfeld | PTH 14 – Morden, Winkler, Plum Coulee, Morris\n PR 332 north – Lowe Farm, Brunkild, Starbuck | PTH 30 ends\nhighway continues as PR 332 |
Question:
how many cities are represented in the intersecting highway category?
Answer:
18