I have a table with rows of year and month

Ex.

```
YearMonth
202001
202002
202003
202006
202007
202010
202011
202012

```

I would like to find the last continuous period

For the example the last continous period is: 202010 - 202012

Other case:

```
YearMonth
202001
202003
202004
202005
202006
202007
202008

```

For this the period is: 202003 - 202008