{ This program is correct wrt the context-free grammar; it tests
  for correct scanning of numerals }

program example;

var x, y: integer;
function gcd(a,b: integer): integer;
begin
    if b <> 0 then gcd := a
    else gcd := gcd(b, a mod b)
end;

begin
    x := readinteger; y := readinteger;
    writeinteger(gcd(x, y));
    a := 3;
    a := 3.5;
    a := 3E3;
    a := 2.563E776;
    a := 1E1;
    a := 0.150E30;
    a := -1.3E+13;
    a := 3.2534E-035;
    a := -0.02E-30;
    a := 35E-5;
    a := a
end.