uses crt;
var s,h:string; i:longint;
begin
clrscr;
write('Nhap vao mot xau:');readln(s);
for i:=length(s) downto 1 do h:=h+s[i];
if h=s then writeln('Day la xau doi xung') else
writeln('Day khong phai la xau doi xung');
readln
end.
/////////////////////////////////
Test: