Binary Minimal

Alice is given a binary string S of lengthN.

She can perform the following operations on string S:

• Select an index 1≤i≤∣S∣ and delete the character Si
• ​.Select an index
• 1≤i≤∣S∣ and flip the character Si
• ​Note that while flipping 1 becomes 0 and vice-versa.

Find the lexicographically smallest string Alice can obtain using at most K operations.