var v:array[1..1000] of char;
f,g:text;
i,con,suma:qword;
cuv:String;
c:char;
rez:qword;
begin
assign (f,'text.in');
assign(g,'text.out');
reset(f);
rewrite(g);
cuv:='';   rez:=0;  suma:=0;  con:=0;
while not eoln(f) do begin
read(f,c);
if c in ['a'..'z','A'..'Z'] then cuv:=cuv+c
else begin
if (cuv<>'') then   begin
suma:=suma+length(cuv);
inc(con); end;
cuv :='';
 end;      end;
if (cuv<>'') then begin
suma:=suma+length(cuv);
inc(con);
end;
{rez:=suma div con; }
write(g,suma/con); readln(f);
close(g);
end.