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 Kotlin (1.0.0) (judge verdict: Accepted)

import java.io.IOException
import java.io.InputStream
import java.io.PrintWriter
import java.util.NoSuchElementException

fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val n = sc.nextInt()
    val v = sc.nextIntArray(n)
    val c = sc.nextIntArray(n)
    val ans = (0 until (1 shl n)).map {
        var x = 0
        var y = 0
        for (i in 0 until n) {
            if (it shr i and 1 == 1) {
                x += v[i]
                y += c[i]
            }
        }
        x - y
    }.max()
    println(ans)
}

class Scanner(private val `in`: InputStream) {
    private val buffer = ByteArray(1024)
    private var ptr = 0
    private var buflen = 0

    companion object {
        private fun isPrintableChar(b: Byte): Boolean = b in 33..126
        private fun isNumericChar(b: Byte): Boolean = b in 48..57
        private fun digit(b: Byte): Int = b - 48
    }

    fun hasNextByte(): Boolean {
        if (ptr < buflen) return true
        ptr = 0
        try {
            buflen = `in`.read(buffer)
        } catch (e: IOException) {
            e.printStackTrace()
        }
        return 0 < buflen
    }

    private fun readByte(): Byte = if (hasNextByte()) buffer[ptr++] else -1

    private fun skipUnprintable() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++
    }

    fun hasNext(): Boolean {
        skipUnprintable()
        return hasNextByte()
    }

    fun next(): String {
        if (!hasNext()) throw NoSuchElementException()
        return buildString {
            var b = readByte()
            while (isPrintableChar(b)) {
                appendCodePoint(b.toInt())
                b = readByte()
            }
        }
    }

    fun nextInt(): Int {
        if (!hasNext()) throw NoSuchElementException()
        var n = 0
        var b = readByte()
        val minus = b.toChar() == '-'
        if (minus) b = readByte()
        if (!isNumericChar(b)) throw NumberFormatException()
        do {
            n *= 10
            n += digit(b)
            b = readByte()
        } while (isNumericChar(b))
        return if (minus) -n else n
    }

    fun nextInts(n: Int): Array<Int> = Array(n) { nextInt() }

    fun nextIntArray(n: Int): IntArray = IntArray(n) { nextInt() }

    fun nextIntArrays(n: Int, m: Int): Array<IntArray> {
        val arrays = Array(m) { IntArray(n) }
        repeat(n) { i -> repeat(m) { j -> arrays[j][i] = nextInt() } }
        return arrays
    }

    fun nextLong(): Long {
        if (!hasNext()) throw NoSuchElementException()
        var n = 0L
        var b = readByte()
        val minus = b.toChar() == '-'
        if (minus) b = readByte()
        if (!isNumericChar(b)) throw NumberFormatException()
        do {
            n *= 10
            n += digit(b)
            b = readByte()
        } while (isNumericChar(b))
        return if (minus) -n else n
    }

    fun nextLongs(n: Int): Array<Long> = Array(n) { nextLong() }

    fun nextLongArray(n: Int): LongArray = LongArray(n) { nextLong() }

    fun nextLongArrays(n: Int, m: Int): Array<LongArray> {
        val arrays = Array(m) { LongArray(n) }
        repeat(n) { i -> repeat(m) { j -> arrays[j][i] = nextLong() } }
        return arrays
    }

}