{
TASK:matrix
LANG:PASCAL
}
var a:array [1..10001] of byte;
    f,k,m,n,i:integer;
begin
 readln(m,n);
 for i:=1 to m*n do
  begin
   read(k);
   a[k]:=a[k]+1;
  end;
 k:=0;
 for i:=1 to 10000 do
   if a[i]<>0 then k:=k+1;
 f:=k div n;
 k:=k mod n;
 if k<>0 then writeln (f+1)
 else writeln (f);
end.

