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 1.8.0) (judge verdict: Wrong Answer)

import java.util.Scanner;

public class Main implements Runnable {

	public static  void main(String[] args) {
		   new Thread(null, new Main(), "", 16 * 1024 * 1024).start(); 
    }
    public void run() {
		
		int A , B , C , K;
	int T = 0;
	Scanner sc = new Scanner(System.in);
	String a = sc.nextLine();
	String b = sc.nextLine();
	String c = sc.nextLine();
	String k = sc.nextLine();
	A = Integer.parseInt(a);
	B = Integer.parseInt(b);
	C = Integer.parseInt(c);
	K = Integer.parseInt(k);
	for(int D = K; D > 0 ;D--) {
		if(A != 0) {
			T = T + 1;
			A = A - 1;
		}else if(B != 0) {
			T = T + 0;
			B = B - 1;
		}else if(C != 0) {
			T = T - 1;
			C = C - 1;
		}
		}
	System.out.println(T);
	}

}