   NxM (     
 )        .
         
 ,   (    ).
        ..,  
    (    
    ).

    ..,    
    .

 
      N  M -   (1<=N<=20,
1<=M<=20).   N   M    -  
 ..      (  0  100).

 
     ,    
   .

  
3 4
1 1 1 1
5 2 2 100
9 4 2 1

  
8

