$(10$ points$)$ Consider the grammar that follows:

$$ stmt $>$ if $$ expr $>$ then $$ stmt $>|$ if $$ expr $>$ then $$ stmt $>$ else $$ stmt $>|a=a+1$

$$ expr $>a=b|a>b$

Prove that this grammar is ambigious.

$(10$ points$)$ Write an equivalent unambiguous grammer for the grammer at question $3.(15$ points$)$ The code below is written in $C++.$ In $C++$ language, when we execute the

statement "int $x=0$; $",x$ becomes a stack$-$dynamic variable. And when we execute the

statement "static int $y=0$; $",$ y becomes a static variable. What is the output of the

program below?