var nrc,lgcc,lg_tot,rez : int64;
    c : char;
    f,g : text;
    separatori,cifre : set of char;
begin
assign(f,'text.in');reset(f);
assign(g,'text.out');rewrite(g);
separatori:=['.',',',';','!','?','-',' ',']','[','/','\',':'];
cifre:=['0'..'9'];
while not eof(f) do
begin
  while not eoln(f) do
  begin
    read(f,c);
      if not (c in ['A'..'Z','a'..'z']) then
      begin
        if lgcc<>0 then
        begin
          inc(lg_tot,lgcc);
          inc(nrc);
          lgcc:=0;
        end;
      end
      else
        inc(lgcc);
  end;
  readln(f);
end;
if lgcc<>0 then
begin
  inc(lg_tot,lgcc);
  inc(nrc);
end;
rez:=lg_tot div nrc;
writeln(g,rez);
close(g);
end.