program dsd;
var f,g:text;
    c:char;
    nr,l:longint;
begin
assign(f,'text.in');reset(f);
assign(g,'text.out');rewrite(g);
l:=0;
nr:=0;
while not eof(f) do begin
                    read(c);
                    while not (c in ['a'..'z','A'..'Z']) do read(f,c);
                    while (c in ['a'..'z','A'..'Z']) do begin
                                                        inc(l);
                                                        read(c);
                                                        end;
                    inc(nr);
                    end;
writeln(g,l div nr);
close(g);
end.