#include <stdio.h>
#define MAX 100
int main()
{
    int arr[MAX],n,i;
    int temp;

    printf("Enter total number of elements: ");
    scanf("%d",&n);
    if(n%2 !=0)
    {
        printf("Total number of elements should be EVEN.");
        return 0;
    }
    for(i=0;i < n;i++)
    {
        scanf("%d",&arr[i]);
    }
    for(i=0;i < n;i+=2)
    {
        temp    = arr[i];
        arr[i]  = arr[i+1];
        arr[i+1]= temp;
    }
    for(i=0;i < n;i++)
    {
        printf("%d ",arr[i]); ///ekhane new er poriborrte space diyese.
    }
    printf("\n"); ///ar ekhane new line print koresi
    return 0;
}