#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <stdbool.h>

void swap(int *xp, int *yp) {
    int temp = *xp;
    *xp = *yp;
    *yp = temp;
}

int *fun(int *arr, int n, bool *b) {
    for (int i = 0; i < n-1; i++) {
        for (int j = 0; j < n-i-1; j++) {
            if (arr[j] % 2 == 0 && arr[j+1] % 2 != 0) {
                swap(&arr[j], &arr[j+1]);
                *b = true;
            }
        }
    }

    int *result = NULL;
    for (int i = 0; i < n; i++) {
        if (arr[i] % 2 == 0) {
            result = arr[i];
            break;
        }
    }
    return result;
}

int main() {
    bool b = false;
    int n = 5;
    int *arr = malloc(sizeof(int) * n);
    arr[0] = 7;
    arr[1] = 8;
    arr[2] = 6;
    arr[3] = 4;
    fun(arr, n, &b);
    return 0;
}