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 C (Clang 10.0.0) (judge verdict: Time Limit Exceeded)


#include <stdio.h>
#include <string.h>
#include <math.h>
#pragma warning(disable : 4996)

int main()
{
    long A, B, C, K;
    long a=0, b=0, c=0;
    int i, j;
    int r;

    scanf("%ld %ld %ld %ld", &A, &B, &C, &K);

    for (i = 0; i < K; i++) {
        if (A > 0) {
            A--;
            a++;
            continue;
        }

        if (B > 0) {
            B--;
            b++;
            continue;
        }

        if (C > 0) {
            C--;
            c++;
            continue;
        }

    }



   
    printf("%ld",a*1+b*0+c*(-1));

    return 0;

}