program Vlad;
var
s,st:string;
A:array[1..10] of string;
i,l,j,k:integer;
latsogl:set of char;
latsogl2:set of char;
prom:set of char;
res:set of char;
begin
writeln('Vvedite stroku: ');
readln(s);
latsogl:=['b','c','d','f','g','h','j','k','l','m','n','p','q','r','s','t','v','w','x','z'];
latsogl2:=[];
prom := [];
res := [];
st:='';
k:=0;
l:=length(s);
for i:=1 to l do
begin
if (s[i]<>' ') and (s[i]<>'!') then st:=st+s[i]
else
begin
k:=k+1;
A[k]:=st;
st:='';
end;
end;

{for i:=1 to k do
writeln(A[i]);}



for i:=1 to k do
begin
     l := length(A[i]);
     for j:=1 to l do
     begin
          if (A[i][j] in latsogl) and (not (A[i][j] in latsogl2)) and (not (A[i][j] in prom)) then
          {begin} prom:= prom + [A[i][j]]; {check} {writeln(A[i][j], ' added to prom'); end;}
          if (A[i][j] in latsogl) and (A[i][j] in latsogl2) then // and (not (A[i][j] in prom)) then
          {begin} res := res + [A[i][j]]; {writeln(A[i][j], ' added to res'); end;}
     end;
     latsogl2 := latsogl2 + prom;
     prom := [];
end;

for i:=1 to 255 do
    if chr(i) in res then writeln(chr(i));

readln;
end.