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 Rust (1.15.1) (judge verdict: Accepted)

fn get_input() -> String {
    let mut word = String::new();
    std::io::stdin().read_line(&mut word).unwrap();
    word.trim().to_owned()
}

fn main() {
    let n: usize = get_input().parse().unwrap();

    let mut v:Vec<i64> = Vec::new();
    let vline = get_input();
    for l in vline.split_whitespace() {
        v.push(l.parse().unwrap());
    }

    let mut c:Vec<i64> = Vec::new();
    let cline = get_input();
    for l in cline.split_whitespace() {
        c.push(l.parse().unwrap());
    }

    let pow:Vec<i64> = (0..(1 << n))
        .map(|i| (0..n)
             .filter(|j| i & (1 << j) > 0)
             .filter(|&i| v[i] > c[i])
             .map(|i| v[i] - c[i])
             .sum())
        .collect();
    let ans = pow.iter().max().unwrap();
    println!("{}", ans);
}