Program texte;
   var litere:set of char;
       ch:char;
       suma,cuvinte:longint;
       f:text;
begin
  assign(f,'text.in'); reset(F); read(f,ch);
  litere:=['a'..'z','A'..'Z']; suma:=0; cuvinte:=0;
  while not eof(f) do begin
     while not eoln(f) do begin
         while not(ch in litere) do read(f,ch);
         if ch in litere then inc(cuvinte);
         while ch in litere do begin
                                inc(suma);
                                read(f,ch);
                                end;
         end;
         readln(f);
         end;
    close(f); assign(f,'text.out'); rewrite(f);
    writeln(f,suma div cuvinte); close(f);
    end.