using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Vásárlás{
    class Program{
        static void Main(){
            int N = int.Parse(Console.ReadLine());
            int[] A = Console.ReadLine().Split().Select(int.Parse).ToArray(),
                  B = Console.ReadLine().Split().Select(int.Parse).ToArray();

            int max = 0, mmax = 0;

            for(int i=0, val; i<N; i++){
                val = A[i] - B[i];
                max = (val + max < val) ? (val + max) : val;
                mmax = (max < mmax) ? (max) : mmax;
                if(val >= 0){
                    //max += val;
                }else{
                    //max = 0;
                }
                /*if (mmax < max){
                    mmax = max;
                }*/
            }
             
            //mmax =  (mmax > 0) ? mmax : 0;

            Console.WriteLine(B.Sum() + ((mmax < 0) ? mmax : 0));
        }
    }
}