Beats 100% by time python short solution
Code

# Code
```python3 []
class Solution:
    def minChanges(self, n: int, k: int) -> int:
        if n == k:
            return 0
        ans = 0
        x = list(f'{n:020b}')
        y = list(f'{k:020b}')
        for i in range(20):
            if x[i] == '1' and  y[i] == '0':
                x[i] = '0'
                ans += 1
        return ans if x == y else -1
```
['Python3']