Yet Another Flipping Problem

Given two binary strings $s$ and $t$ each of length $n$, determine whether it is possible to convert $s$ to $t$ in **exactly** $k$ operations of the following type: Select any non-empty substring of $s$ and flip each character of that substring. For example, $0\underbar{11010}1011$ can be converted to $0\underbar{00101}1011$ in one operation. ### Input - The first line of input will contain a si