var f,g:text;
    x:char;
    nr,s:longint;
    numara:boolean;
	lit:set of char;
begin
     nr:=0;
     s:=0;
     assign(f,'text.in');reset(f);
     numara:=false;
     lit:=['A'..'Z','a'..'z'];
     while not eof(f) do
     begin
          read(f,x);
          if x in lit then
             numara:=true;
          if x in lit then
             s:=s+1
          else
              if (not(x in lit)) and (numara=true) then
              begin
                   nr:=nr+1;
                   numara:=false
              end
     end;
     close(f);
          if x in ['A'..'Z','a'..'z'] then
             nr:=nr+1;
          assign(g,'text.out');rewrite(g);
          write(g,s div nr);
          close(g);
end.