Program Affich_sans_redondance;
Var T : Array [1..20] of Char;
n, i, j : Integer;
Begin 
Repeat
Writeln('Donner un entier');
Readln(n);
Until n in [3..20] ;
For i:=1 To n Do Repeat
Writeln('Saisir la case d''ordre ', i);
Readln(T[i]);
Until upcase(T[i]) in ['A'..'Z'] ;
For i:=1 To 20 Do Writeln (T[i], ' ');
Writeln;
Writeln;
Writeln(T[1], ' ');
For i:=2 To 20 Do 
Begin
j:=i;
While (j>2) and (T[i]<>T[j-1]) Do j:=j-1;
If T[i] <>T[j-1] Then Write (T[i], ' ');
End;
End.