import java.io.*;
import java.util.*;

class Main  // O(n^2)
{
	private static final Scanner cin = new Scanner(System.in);

	public static void main(String[] args)
	{
		int n = cin.nextInt();

		int[] x = new int[n];
		int[] y = new int[n];

		for(int i = 0; i < n; i++) {
			x[i] = cin.nextInt();
			y[i] = cin.nextInt();
		}

		int[][] dp = new int[n][n];
		int[][] kk = new int[n][n];

		for(int i = 0; i < n; i++)
			kk[i][i] = i;

		for(int m = 1; m < n; m++) {
			for(int i = 0; i < n - m; i++) {
				int j = i + m;

				dp[i][j] = Integer.MAX_VALUE;
				int kmin = kk[i][j-1];
				int kmax = Math.min(kk[i+1][j], j - 1);

				for(int k = kmin; k <= kmax; k++) {
					int l = dp[i][k] + dp[k+1][j] + x[k+1] - x[i] + y[k] - y[j];
					if(dp[i][j] > l) { kk[i][j] = k; dp[i][j] = l; }
				}
			}
		}

		System.out.println(dp[0][n-1]);
	}
}