var
        s:ansistring;
        f:text;
        n,k,c,i:int64;
begin
        assign(f,'text.in');
        reset(f);
        read(f,s);
        n:=0;
        k:=0;
        c:=0;
        i:=1;
        while not eof(f)do
                begin
            if not (s[i] in['a'..'z']) and not (s[i] in ['A'..'Z'])  then
                        begin
                        if c<>0 then
                                begin
                                n:=n+c;
                                k:=k+1;
                                end;
                        c:=0;
                        end
                                             else c:=c+1;
            i:=i+1;
            end;
        close(f);
        assign(f,'text.out');
        rewrite(f);
        if k<>0 then write(f, trunc(n/k));
        close(f);
end.