Operation between data of different bit lengths

I've tried performing a multiplication operation with integers (Int[N]) of different bit lengths and encountered an error. It seems that operations between different bit lengths are not currently supported for Int[N]. Is it possible to create a new class that supports operations between differing bit lengths? If so, how should I specify the bit length of each argument in the definition of the operation function?
```
a = Int[12](20)
b = Int[8](15)
c = a * b
print(c)

error: unsupported operand type(s) for *: 'Int[12]' and 'Int[8]'
```