Easy solution
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```cpp []
class Solution {
public:
    int minChanges(int n, int k) {
        //if(n==k)
        //    return 0;
        
        bitset<32> b1(n),b2(k);
        string N=b1.to_string(),K=b2.to_string();
        int c=0;
        for(int i=0;i<32;i++)
            if(N[i]=='1' && K[i]=='0')
                c++;
            else if(N[i]=='0' && K[i]=='1')
                return -1;
        return c;
    }
};
```
['C++']