how to about my code i cant call function inline function

Here is my code:

```
function antus(){
   global $vidi;
   $vidi = random_int(100, 999);
}

function bntus(){
   global $hexa;
   antus();
   $hexa = 5 * $vidi;
   echo $hexa;
}

bntus();

```

Thank you