Problem:
Score : 200 points

Problem Statement

There are N gems. The value of the i-th gem is V_i.

You will choose some of these gems, possibly all or none, and get them.

However, you need to pay a cost of C_i to get the i-th gem.

Let X be the sum of the values of the gems obtained, and Y be the sum of the costs paid.

Find the maximum possible value of X-Y.

Constraints

All values in input are integers.

1 \leq N \leq 20

1 \leq C_i, V_i \leq 50

Input

Input is given from Standard Input in the following format:

N
V_1 V_2 ... V_N
C_1 C_2 ... C_N

Output

Print the maximum possible value of X-Y.

Sample Input 1

3
10 2 5
6 3 4

Sample Output 1

5

If we choose the first and third gems, X = 10 + 5 = 15 and Y = 6 + 4 = 10.
We have X-Y = 5 here, which is the maximum possible value.

Sample Input 2

4
13 21 6 19
11 30 6 15

Sample Output 2

6

Sample Input 3

1
1
50

Sample Output 3

0

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;

class Bmondai
{
    static void Main()
    {
        var N = Int32.Parse(Console.ReadLine());
        var V = Console.ReadLine().Split(' ').Select(x=>Int32.Parse(x)).ToArray();
        var C = Console.ReadLine().Split(' ').Select(x => Int32.Parse(x)).ToArray(); ;
        var ans = long.MinValue;
        var count = Math.Pow(2, N);
        for (int i=0;i<count;i++)
        {
            var bitArray = new bool[N];
            for (int j=0;j<N;++j) bitArray[j] = (1 & i >> j) == 1;
            var X = 0L;
            var Y = 0L;
            for (int j=0;j<N;++j)
            {
                if (bitArray[j])
                {
                    X += V[j];
                    Y += C[j];
                }
            }
            var sa = X - Y;
            if (ans < sa) ans = sa;
        }
        Console.WriteLine(ans);
    }
}