Write a function that rearranges an integer into its largest possible value. 
```python
super_size(123456) # 654321
super_size(105)    # 510
super_size(12)     # 21
```
``` haskell
superSize 123456 `shouldBe` 654321
superSize    105 `shouldBe`    510
superSize     12 `shouldBe`     21
```
If the argument passed through is single digit or is already the maximum possible integer, your function should simply return it.
def super_size(n):
    li = list()
    p = ''
    for i in str(n):
        li.append((i))
    for j in range(len(li)):
        p+=max(li)
        li.remove(max(li))
    return int(p)
def super_size(n):
    li = list()
    p = ''
    for i in str(n):
        li.append((i))
    for j in range(len(li)):
        p+=max(li)
        li.remove(max(li))
    return int(p)