Write $($define$)$ a function named get$\_$first, that takes one argument $($you can safely assume that arguments will always be a str with a length of at least one$).$ When this function is called, it should return a str that contains only the first character in the argument.

Examples:

get$\_$first$(\text{'}$Hello$!\text{'})$ will return $\text{'}$H$\text{'}$

get$\_$first$(\text{'}$one two three'$)$ will return $\text{'}$o$\text{'}$

get$\_$first$(\text{'}$abcdefg$\text{'})$ will return $\text{'}$a$\text{'}$