var c:char;
    nr,lg,k:longint;
    f,g:text;
function cifra(x:char):boolean;
 begin
  if (x>='a') and(x<='z')
   or (x>='A')and(x<='Z') then cifra:=true
                          else cifra:=false;
 end;

begin
assign(f,'text.in ');reset(f);
assign(g,'text.out');rewrite(g);
lg:=0;k:=0;nr:=0;
while not eoln(f) do
 begin
  read(f,c);
  if cifra(c)=true then inc(k)
                   else if k<>0 then begin
                                       inc(nr);
                                       lg:=lg+k;
                                       k:=0;
                                      end;

 end;
if k<>0 then begin
              inc(nr);
              lg:=lg+k;
              k:=0;
             end;

if (nr<>0) and(lg<>0) then write(g,lg div nr)
                      else write(g,0);
close(f);
close(g);
end.