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: Wrong Answer)

import java.util.Scanner;
public class Main{
	int o,h,s,e;
	double q,w,a;
	String  i,l,k;
	Scanner scan=new Scanner(System.in);
	public void output() {
int[] date=new int[4];
for(o=0;o<4;o++) {
	date[o]=scan.nextInt();
}
while(true) {
	if(date[0]!=0) {
		date[3]-=date[0];
		h=date[0];
		date[0]=0;
		if(date[3]<=0) {
			break;
		}
	}else if(date[1]!=0) {
		date[3]-=date[1];
		date[1]=0;
		if(date[3]<=0) {
			break;
		}
	}else if(date[2]!=0) {
h-=1;
	date[3]-=1;	
	if(date[3]<=0) {
		break;
	}
	}
	
}
System.out.println(h);
	}
	public static void main(String[] args) {
		Main p=new Main();
		p.output();
	}
}