program texte;
{const litera=['q','Q','W','w','E','e','R','r','T','t','y','Y','U','u','i','o','I','O','p','P',
'A','a','S','s','d','D','f','F','g','G','h','H','j','J','k','K','l','L',
'z','Z','X','x','c','C','v','V','B','b','n','N','m','M'];}
var f,g:text;
s,prec:string[1];
litere:string;
k,lit,cuv:longint;
begin
  assign(f,'text.in'); assign(g,'text.out');
  reset(f); rewrite(g);
  s[1]:=' '; prec[1]:=' ';
  lit:=0; cuv:=0; k:=0;
  litere:='qwertyuioplkjhgfdsazxcvbnmQWERTYUIOPLKJHGFDSAZXCVBNM';
  while not eof(f) do
  begin
    read(f,s[1]);
    if pos(s[1],litere)<>0 then
      begin
        lit:=lit+1;
        if k=0 then cuv:=cuv+1;
        k:=1;
      end
    else k:=0;
  end;
  writeln(g,lit/cuv:0:0);
  close(f); close(g);
end.