test.pl0

const
  m = 7, n = 85;
var
  i,x,y,z,q,r;
procedure multiply;
var
  a,b;
begin
  a := x; b := y; z := 0;
  while b > 0 do
    begin
      if odd(b) then z := z+a;
      a := 2*a; b := b/2;
    end
  end;

procedure divide; 
var w;
begin
  r := x; q := 0; w := y;
  while w <= r do w := 2*w;
  while w > y do
    begin q := 2*q; w := w/2;
      if w <= r then
      begin
        r := r-w; q := q+1;
      end
    end
end;

procedure gcd;
var
  f,g;
begin
  f := x; g := y;
  while f # g do
    begin if f<g then g := g-f;
          if g<f then f := f-g;
    end;
  z := f;
end;

begin
  i:=1;
  while i#0 do
  begin
    x := m; y := n; call multiply;
    x := 25; y := 3; call divide;
    x := 84; y := 36; call gcd;
    i:=i-1;
  end;
end.