1.
var s:string;
begin
write('Nhap xau: '); readln(a);
write('Xau in hoa la: ',upcase(a));
readln
end.
2.
var a,b:string;
i:byte;
begin
write('Nhap xau a: '); readln(a);
for i:=1 to length(a) do
if a[i] in ['0'..'9'] then b:=b+a[i];
write('Xau b la : ',b);
readln
end.