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        Signature
      
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        /s/ Tricia Branker, Attorney-in-Fact
      
      
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        Stock symbol
      
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        MTRY
      
      
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        Transactions as of
      
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        Sep 30, 2021
      
      
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        Transactions value $
      
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        $0
      
      
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        Form type
      
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        3
      
      
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        Date filed
      
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        9/30/2021, 05:51 PM
      
 
     
   
 
  
    Transactions Table
  
  
    
      
        
          | Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes | 
      
      
          
            | holding | MTRY | Common Stock |  |  |  |  |  | 1.91M | Sep 30, 2021 | See footnote | F1, F2 | 
          
            | holding | MTRY | Common Stock |  |  |  |  |  | 35K | Sep 30, 2021 | Direct |  | 
      
    
   
  
    * An asterisk sign (*) next to the price indicates that the price is likely invalid.
  
  
    Explanation of Responses:
  
  
  
    Remarks:
  
  See Exhibit 24.1 - Power of Attorney