asterisk dialplan edit

i need fixing and editing on 40 dialp[an lines list of samples gotoif len $number=7,3 exten 2:file18 gotoif LEN $number >3?play file18:goto exten333 saynumber {parts of a string} play file and saynumber goto if timeout 3 times gotoif invalid 3 times gotoif invalid 4 times exten => i,1,Set(NUMINVALID=$[${NUMINVALID}+1]}) exten => i,2,Gotoif($["${NUMINVALID}" < "4"]?:10) exten => i,3,Background(invalid)