Let

$\backslash$Sigma

$=$

$\{$

$$

$,$

$$

$\}$

$\backslash$Sigma $=\{$a$,$b$\}$ and consider the language

$\{$

$$

in

$\backslash$Sigma

$$

$$

$$

has the substring

$$

$$

$$

$\}$

$\{$w in $\backslash$Sigma

$$

$$w has the substring aab$\}$

Below select its minimum pumping length.