Walk Alone has two rows of matches, each of which contains n matches. He defines the distance between them as d=∑ni=1∣ai−bi∣, where ai and bi represent the height of the i-th match in the first row and the second row, respectively. Walk Alone wants to beautify the matches by shortening the distance, and you are asked to find out the minimum distance after performing at most one swap within one row. Note that the height can be negative.