Problem:
Score : 200 points

Problem Statement

We have A cards, each of which has an integer 1 written on it. Similarly, we also have B cards with 0s and C cards with -1s.

We will pick up K among these cards. What is the maximum possible sum of the numbers written on the cards chosen?

Constraints

All values in input are integers.

0 \leq A, B, C

1 \leq K \leq A + B + C \leq 2 \times 10^9

Input

Input is given from Standard Input in the following format:

A B C K

Output

Print the maximum possible sum of the numbers written on the cards chosen.

Sample Input 1

2 1 1 3

Sample Output 1

2

Consider picking up two cards with 1s and one card with a 0.
In this case, the sum of the numbers written on the cards is 2, which is the maximum possible value.

Sample Input 2

1 2 3 4

Sample Output 2

0

Sample Input 3

2000000000 0 0 2000000000

Sample Output 3

2000000000

Solution in Java (OpenJDK 11.0.6) (judge verdict: Runtime Error)


import java.util.*;
public class Main{

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);

        int a = scan.nextInt();
        int b = scan.nextInt();
        int c =scan.nextInt();
        int k = scan.nextInt();

        List<Integer> lista = Collections.nCopies(a,1);
        List<Integer> listb = Collections.nCopies(b,0);
        List<Integer> listc = Collections.nCopies(c,-1);

        List<Integer> main = new ArrayList<>();
        main.addAll(lista);
        main.addAll(listb);
        main.addAll(listc);

        int sum  = 0;
        Collections.sort(main);
        for(int i = main.size()-k ; i < main.size() ; i++){
            sum += main.get(i);
        }
        System.out.println(sum);


    }
}