.
, , , . \n, n 0 9.
, , ( ) ( ), , \2 \1.
3 ( )
.
, , ,
) ,
) , .
.., :
.. (1956)
, .
html-
, , . , . .
HTML4 Javascript.
HTML5 , pattern input. C .
,
<input type="text" title=": 2 . 6 "
pattern="[a-zA-Z]{2}\d{6}" />
HTML5 , Submit. " ", .
4 ( )
:
+7 8‑‑--.
( :invalid). ,
\d . "" .