program p152n80;
{$APPTYPE CONSOLE}

uses
  SysUtils;

const
  nmax = 20;


function CountDiffChar(str: string; bw, ew: Integer): Integer;  //Îáðàáàòûâàåò ñëîâî
var
  i: Integer;
  j: Char;
  a: set of char;
begin
  a:=[];
  result:=0;
  for i:=bw to ew do
    a:=a+[str[i]];
  for j:= #0 to #255 do
    if j in a then
      inc(Result);
end;

procedure StringExec(const str: string; var maxStr: string; var max: Integer);  //Îáðàáàòûâàåò ñòðîêó
var
  i, j, iw, bw, ew, len: integer;
begin
  i:=1;
  while i<Length(str) do
  begin
    len:=0;
    while (i<Length(str)) and (str[i]=' ') do  //Ïðîïóñê ïðîáåëîâ
      inc(i);
    iw:=0;
    while (str[i]<>' ') and (i<Length(str)) do  //Îáðàáîòêà ñëîâà.
    begin
          inc(i); inc(iw);
    end;
    bw:=i-iw;
    if bw = 1 then
      ew:=i-1
    else
    begin
      ew:=i;
      inc(iw);
    end;
    len:=CountDiffChar(str, bw, ew);
    if len>max then
    begin
      max:=len;
      maxStr:=Copy(str, bw, iw)
    end
  end
end;
procedure PrintStr(const str: string);
var
  i:integer;
begin
  for i:=1 to nmax do
  write(str[i]);
end;

procedure SearchInFile(const input: Textfile);    //Îáðàáàòûâàåò ôàéë
var
  i, bw_max, ew_max, max: Integer;
  str, maxStr: string;
begin
  max:=0;
  maxStr:='';
  while not eof(input) do
  begin
    readln(input, str);
    StringExec(str, maxStr, max);
  end;
  PrintStr(maxStr);
end;


var                                  //main
  input, output: Textfile;
  n:integer;
begin
  AssignFile(input, '1.txt');
  reset(input);
  SearchInFile(input);
  readln; Readln; Readln;
end.