var mat:array[1..16,1..16] of longint;
    n,m,i,j:1..16;
    sum:int64;
    f:text;
    
    Begin
     assign(f,'flip.in');
     reset(f);
     readln(f,n,m);
     for i:=1 to n do begin
      for j:= 1 to m do
       read(f,mat[i,j]);
       readln(f);
       end;
     close(f);
     sum:=0;
     for i:=1 to n do
      for j:=1 to m do
       if mat[i,j]>0 then sum:=sum+mat[i,j];
     assign(f,'flip.out');
     rewrite(f);
     write(f,sum);
     close(f);
    End.