program Project1;
var mas:array of char;
n,i,j:integer;
flag:boolean;
begin
writeln('Input n');
readln(n);
setlength(mas,n);
writeln('Input array of symbols');
for i:=1 to n do
read(mas[i]);
flag:=false;
for i:=1 to n do
begin
flag:=false;
for j:=1 to n do
begin
if (j=i) then continue;
if (mas[j]=mas[i]) then
begin
flag:=true;
break;
end;
end;
if (flag=false) then write(mas[i],' ');
end;
readln;
end.