What is the output from the code snippet below when the input file test.txt is the single line

"Who am I? $24601!"$

ifstream in$\_$file;

char ch;

in$\_$file.open$("$test$.$txt$")$;

while $($in$\_$file.get$($ch$))$

$\{$

if $($isdigit$($ch$))$

$\{$

cout $<<$ ch;

$\}$

$\}$