/*
ID: aadithyaa1
LANG: JAVA
TASK: marathon
 */
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Scanner;
import java.util.*;

class marathon {
  public int distance(int x, int y) {
    return Math.abs(x-y);
  }
  public static void main(String[] args) throws IOException {
    Scanner sc = new Scanner(new File("marathon.in"));
    PrintWriter pw = new PrintWriter(new File("marathon.out"));
    int N = sc.nextInt();
    ArrayList<ArrayList> checkpoints = new ArrayList<>();

    for(int i = 1; i <= 2*N; i++) {
      ArrayList<Integer> checkpair = new ArrayList<>();
      checkpair.add(sc.nextInt());
      checkpair.add(sc.nextInt());
      checkpoints.add(checkpair);
    }
    int max = 0;
    int total = 0;
    for(int i = 0; i < N; i++) {
      total += distance(checkpoints.get(i).get(0),checkpoints.get(i).get(1));
      if(distance(checkpoints.get(i).get(0),checkpoints.get(i).get(1)) >temp) {
        max = distance(checkpoints.get(i).get(0),checkpoints.get(i).get(1));
      }
    }
    pw.println(total - max);
    pw.close();



  }


}