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 JavaScript (Node.js 12.16.1) (judge verdict: Wrong Answer)

"use strict"
function main(arg) {
    let getInt = arg.trim().split(" ")[3];
    let oneCount = arg.trim().split(" ")[0];
    let zeroCnt = arg.trim().split(" ")[1];
    let minusCnt = arg.trim().split(" ")[2];

    let result = 0;

    if(oneCount == 0 && zeroCnt == 0 && minusCnt == 0){
        console.log(0);
        return;
    }

    if(getInt > 0){
        
        if(getInt > oneCount){
            result = oneCount * 1;   
        }else{
            result = getInt * 1;
        }
        getInt = getInt - oneCount;
    }

    if(getInt > 0){
        getInt = getInt - zeroCnt;
    }

    if(getInt > 0){
        result = result + (getInt * - 1);
    }

    console.log(result);

}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));