------
## 最终结论
```python
def find_Max_Num(digits, n):
    digits.sort(reverse=True)
    max_num_str = ''.join(map(str, digits))
    return int(max_num_str)

# Test cases
assert find_Max_Num([1,2,3],3) == 321
assert find_Max_Num([4,5,6,1],4) == 6541
assert find_Max_Num([1,2,3,9],4) == 9321
```