How to create binary column based on starts character in other column in Oracle SQL Developer?

I have table like below in Oracle SQL Developer:

col1
-------
Regio Apo
Makreg One15
Regio Kawalisz
Makreg Podl
Makrego BB
AAA

And based on values in "col1" I need to create new column "col2". It should be binary columns:

• When value in "col1" starts with "M" return 1 in "col2"
• When value in "col1" starts with "R" return 0 in "col2"
• rather all values in "col1" start with M or R but just in case it starts with another letter give NULL

So as a result I need something like below:

col1             col2
-----------------------
Regio Apo      | 0
Makreg One15   | 1
Regio Kawalisz | 0
Makreg Podl    | 1
Makrego BB     | 1
AAA            | NULL

How can I do that in Oracle SQL Developer ?

>Solution :

CASE seems to be the most obvious:

SQL> with test (col1) as
  2    (select 'Regio Apo'      from dual union all
  3     select 'Makreg One15'   from dual union all
  4     select 'Regio Kawalisz' from dual union all
  5     select 'Makreg Podl'    from dual union all
  6     select 'Makrego BB'     from dual union all
  7     select 'AAA'            from dual
  8    )
  9  select col1,
 10    case when substr(col1, 1, 1) = 'M' then 1
 11         when substr(col1, 1, 1) = 'R' then 0
 12         else null
 13    end cols
 14  from test;

COL1                 COLS
-------------- ----------
Regio Apo               0
Makreg One15            1
Regio Kawalisz          0
Makreg Podl             1
Makrego BB              1
AAA

6 rows selected.

SQL>