if (!-f $request_filename){
        set $rule_1 1$rule_1;
}
if (!-d $request_filename){
        set $rule_1 2$rule_1;
}
if ($rule_1 = "21"){
        rewrite ^(.*?)/index\.(html|htm|php) $1/index.$2 last;
        rewrite ^(.*?)/(.*) $1/index.php?u=$2 last;
}