import Foundation

let filePath = CommandLine.arguments[1]
let content =  try? String(contentsOfFile: filePath, encoding: .ascii)
let lines = content!.split(separator: "\n")
var leftList: [Int] = []
var rightList: [Int] = []
for line in lines {
    let lr = line.split(separator: " ")
    leftList.append(Int(lr[0])!)
    rightList.append(Int(lr[1])!)
}
leftList.sort()
rightList.sort()
print(zip(leftList, rightList).reduce(0, { sum, lr in sum + abs(lr.0 - lr.1) }))