uses crt;
var a,b: array[1..100] of integer;
i,n,d,k,j: integer;
begin
clrscr;
write ('nhap n: '); readln (n);
for i:=1 to n do
begin
write ('nhap phan tu thu ',i,': '); readln (a[i]);
end;
d:=0;
for i:=1 to n do
begin
if d=1 then begin k:=k+1; b[k]:=a[i-1]; end;
d:=0;
for j:=n downto 1 do
if a[i]=a[j] then d:=d+1;
end;
writeln (k);
for i:=1 to k do
write (b[i]:4);
readln;
end.

Uses Crt;

Var S : String;

       i,j,k,f : Integer;

Begin

 Clrscr;

 Write('Nhap so : '); Readln(n);
 For i:=1 to n do
  Begin

   Write('Nhap xau thu ',i,' : '): Readln(S[i]):

  End;
 For i:=1 to n-1 do
  For j:=i to n do If S[i] = S[j] then 
   For k:=1 to n do If S[k] = S[i] then S[k]:='';

 For i:=1 to n do If S[i] <>'' then Writeln(S[i]):

 Writeln(S);

 Readln

End.