var a:string;
    i,c,k,nr,b:integer;
    j:real;
    f,g:text;
begin
 assign(f,'text.in');reset(f);
 assign(g,'text.out');rewrite(g);
 readln(f,a);
 close(f);
 for i:=1 to length(a) do begin
                          if (a[i]>='a') and (a[i]<='z') then begin
                                                             inc(k);
                                                             b:=c;
                                                             c:=1;
                                                            end
                          else if (a[i]>='A') and (a[i]<='Z') then begin
                                                                  inc(k);
                                                                  b:=c;
                                                                  c:=1;
                                                                 end
                          else begin
                                b:=0;
                                c:=0;
                               end;
                          if c<>b then inc(nr);

                          end;


j:=k/nr;
write(g,trunc(j));
close(g);
end.