Find context$-$free grammars for the following languages $($with n $0,$ m $0,$ k $0).($a$)$ L $=\{$a nbmc k : n $=$ m or m $$ k$\}.($b$)$ L $=\{$a nbmc k : n $=$ m or m $$ k$\}.($c$)$ L $=\{$a nbmc k : k $=$ n $+$ m$\}.($d$)$ L $=\{$a nbmc k : n $+2$m $=$ k$\}.($e$)$ L $=\{$a nbmc k : k $=|$n $$ m$|\}.($f$)$ L $=\{$w in $\{$a$,$ b$,$ c$\}*$ : na $($w$)+$ nb $($w$)$ nc $($w$)\}.($g$)$ L $=\{$a nbmc k $,$ k $$ n $+$ m$\}.($h$)$ L $=\{$a nbmc k : k $3\}.$