(*D+*)PROGRAM RECURSIVEGCD; 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 (* OF GCD*); PROCEDURE TRY( A, B: INTEGER);BEGIN  WRITELN( A:7, B:7, GCD(A,B):7  );END; BEGIN TRY( 18, 27 );      TRY( 312, 2142 );      TRY( 61, 53 );      TRY( 98, 868 )END.