for $($int $i=0$;$i<mn\; id="EditorElement\_63439">1</mn>$;$i++$

$1$

a$.$ pop $($ch$)$ ;

if $($ch $!=s[i]$

i

flag$=1$;

break;

$\}$

$\}$

A$.$ remove one item from stack and save it in a$.$

B$.$ remove one item from stack and save it in char.

C$.$ sends char to stack called a$.$

D$.$ peek one item from stack and save it in char.