const semne=['.','!','?'];
var  s:string;
     f,g:text;
     i,c:integer;
begin
assign(f,'text.in');reset(f);
assign(g,'text.out');rewrite(g);
read(f,s);
for i:=1 to length(s) do
if (s[i]=' ') or (s[i] in semne) then
if ((s[i-1]>='a') and (s[i-1]<='z')) or ((s[i-1]>='A')and (s[i-1]<='Z')) then c:=c+1;
write(g,length(s)/c:4:2);
close(f);
close(g);
end.