program efgsdgdf;

var s:string;
    k,m:integer;
    f,g:text;
    c:char;
    ss:longint;

begin
assign(f,'text.in'); reset(f);
assign(g,'text.out'); rewrite(g);
ss:=0;
k:=0;
while not eof(f) do
   begin
   read(f,c);
   s:='';
   while ((c>='a') and (c<='z')) or ((c>='A') and (c<='Z')) do
      begin
      s:=s+c;
      read(f,c);
      end;
   if s<>'' then begin
                 ss:=ss+length(s);
                 k:=k+1;
                 end;
   end;
m:=trunc(ss/k);
write(g,m);
close(f);
close(g);
end.