integer procedure Euclid(m,n);
	  value m,n; 
	  integer m,n;
	  begin 
		integer r;
		if m < n then Euclid(n,m);
	   LOOP:
		r := m - entier(m / n) * n;
		if r = 0 then goto EXIT; 
		m := n; 
		n := r; 
		goto LOOP;
	   EXIT:
	        Euclid := n;
	  end Euclid;
begin 
    integer m,n;
    ininteger(0,m);
    ininteger(0,n);
    outinteger(1, Euclid(m,n));
end