val N:ℕ;
val M:ℕ;

type int   = ℤ[-N,N]; 
type elem  = ℤ[-M,M];
type array = Array[N,elem];

proc maximumElement(a:array,n:int): int
{
  var m:int;
  if n = 0 then
    m ≔ -1;
  else
  {
    m ≔ -1;
    for var i:int ≔ 0; i < n; i ≔ i+1 do
    {
      if a[i] > m then m := a[i];
    }
  }
  return m;
}