title: Group by on two tables and then append results and remove duplicates
body: <p>I have 2 tables with multiple columns in each of them. As can be seen below the column headers are not the same name. 
  I would like to do a GROUP BY on the first and second column of EACH table and then in the output, the results should be appended and not have any duplicates. Also the results only needs the first two columns as the output.</p>
  
  <p>Tablename = STAT</p>
  
  <pre><code>Region   Brand  M08 
  -----------------
  P1       A      xx     
  P1       A      yy    
  P2       B      zz     
  P2       C      yy      
  P3       A      uu     
  P3       B      ii    
  P3       C      oo   
  </code></pre>
  
  <p>TABLE NAME = MI</p>
  
  <pre><code>RegDes   P4Brand  M08 
  -----------------   
  P2       B        er    
  P2       C        tr     
  P3       A        ty     
  P3       B        ew    
  P4       C        yu  
  P4       A        tr     
  P4       B        ty     
  P5       C        yu 
  </code></pre>
  
  <p>TABLE NAME = EXPECTED_OUTPUT</p>
  
  <pre><code>Region   Brand   
  -----------------  
  P1       A              
  P2       B          
  P2       C         
  P3       A          
  P3       B         
  P4       C     
  P4       A         
  P4       B        
  P5       C    
  </code></pre>
  
  <p>I need some help writing the SQL script for this. I have already created the schema for the 3 tables .
  The final output will be inserted into the Table: EXPECTED_OUTPUT</p>