Sum consecutive observations in a dataset SAS

I have a dataset that looks like:

  Hour    Flag
    1       1
    2       1
    3       .
    4       1
    5       1
    6       .
    7       1
    8       1 
    9       1
    10      . 
    11      1
    12      1
    13      1
    14      1

I want to have an output dataset like:

   Total_Hours   Count
        2          2
        3          1
        4          1

As you can see, I want to count the number of hours included in each period with consecutive "1s". A missing value ends the consecutive sequence.

How should I go about doing this? Thanks!

You'll need to do this in two steps. First step is making sure the data is sorted properly and determining the number of hours in a consecutive period:

PROC SORT DATA = <your dataset>;
  BY hour;
RUN;

DATA work.consecutive_hours;
  SET <your dataset> END = lastrec;

  RETAIN
    total_hours 0
  ;

  IF flag = 1 THEN total_hours = total_hours + 1;
  ELSE
    DO;
      IF total_hours > 0 THEN output;
      total_hours = 0;
    END;
  /* Need to output last record */
  IF lastrec AND total_hours > 0 THEN output;

  KEEP 
    total_hours
  ;
RUN;

Now a simple SQL statement:

PROC SQL;
  CREATE TABLE work.hour_summary AS
  SELECT
    total_hours
   ,COUNT(*) AS count
  FROM
    work.consecutive_hours
  GROUP BY
    total_hours
  ;
QUIT;