Pascal 用递归求最大公约数

var
  a, b: Integer;

function gcd(m, n: Integer): Integer;
begin
  if (n = 0) then
    result := m
  else
    result := gcd(n, m mod n);
end;

begin
  readln(a, b);
  Writeln(gcd(a, b));
  readln;

end.