const abc='abcdefghijklmnopqrstuvwxyz';
did='ABCDEFGHIJKLMNOPQRSTUVWXYZ';
begin
zsk:=0;
i:=0;
assign(failas, 'prad.txt');
reset(failas);
/////////////////////////////////////////////////zodzius is bylos keliame i masyva
while not Eof(failas) do //nuskaitom byla
begin
read(failas, r);
nr:=pos(r, did); //keiciam didziasias raides i mazasias
if nr>0 then begin
keit:= copy(abc, nr, 1);
r:=keit[1];
end;
nr:=pos(r, abc); //atrenkam raides
if nr>0 then zodis1:=zodis1+r //ir kuriam zodzius
else begin
if zodis1<>'' then begin
zsk:=zsk+1;
nr:=zsk;
for i:=1 to nr do
begin
if arr[i]=zodis1 then zsk:=zsk-1;
if (i=nr) and (zsk=nr) then begin
arr[i]:=zodis1;
zodis1:='';
end;
end;
end;
zodis1:='';
end;
end;
if zodis1<>'' then begin //dar karta patikriname, kad nuskaitytu paskutini simboli
zsk:=zsk+1;
nr:=zsk;
for i:=1 to nr do
begin
if arr[i]=zodis1 then zsk:=zsk-1;
if (i=nr) and (zsk=nr) then arr[i]:=zodis1;
end;
end;
close(failas);