PROGRAM RECURSIVEGCD(OUTPUT);
    
VAR X,Y,N : INTEGER;
    
FUNCTION GCD(M,N: INTEGER): INTEGER;
BEGIN    IF N=0 THEN GCD := M
         ELSE GCD := GCD(N,M MOD N)
END;
    
PROCEDURE TRY(A,B :INTEGER);
BEGIN     WRITELN(A,B,GCD(A,B))
END;
    
BEGIN TRY(18,27);
      TRY(312,2142);
      TRY(61,53);
      TRY(98,868)
END.