let makegrid m n =
  let mrows acc1 m1 m2 =
   match m1,m2 with
     | m2,m1 when m1 <= m2 ->
       (
        let nrows acc  n1 n2 =
         match n1,n2 with
         | n2,n1 when n1 <= n2 -> mrows ([n1] @ acc) (n1+1) n2
         | n2,n1 -> mrows (acc :: acc1) (m1+1) m2
       )
     | m2,m1 ->
   in nrows [] 0 4
  in mrows [] 0 4