uses crt;
var a,dv,ch,tr,ng:integer;
begin
clrscr;
write('nhap bien so:'); readln(a);
dv:=a mod 10;
ch:=a div 10; ch:=ch mod 10;
tr:=a div 100; tr:=tr mod 10;
ng:=a div 1000; ng:=ng mod 10;
if dv=ch=tr=ng then writeln('day la bien so xe tu quy')
else writeln('day khong la bien so xe tu quy);
readln;
end.
uses crt;
var a,dv,ch,tr,ng:integer;
begin
clrscr;
write('nhap bien so:'); readln(a);
dv:=a mod 10;
ch:=a div 10; ch:=ch mod 10;
tr:=a div 100; tr:=tr mod 10;
ng:=a div 1000; ng:=ng mod 10;
if dv=ch=tr=ng then writeln('day la bien so xe tu quy')
else writeln('day khong la bien so xe tu quy);
readln;
end.