Problem $1$: Context Free Grammar I $[5,5$ pts$]$

$1.$ Give context$-$free grammar for the language below:

L : $\{$s in $\{$a$,$ b$\}||$s$|$ is odd, and a is in the middle position$\}$

$2.$ Give context$-$free grammar for the language below:

L : $\{$x in $\{0,1\}|$ the symbol at position i is the same as the symbol at position i$+3,|$x$|>=4\}$